Equity [Abstract] Schedule of Limited Partners' Capital Account by Class [Table] Schedule of Limited Partners' Capital Account by Class [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Class A Common Stock Common Class A [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Non-Employee Director Non Employee Director [Member] Non Employee Director [Member] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] 2016 Plan 2016 Incentive Plan [Member] 2016 Incentive Plan 2006 Incentive Plan Two Thousand Six Stock Incentive Plan [Member] Two thousand six stock incentive plan. Amended and Restated 1997 Employee Stock Purchase Plan Amended And Restated Nineteen Ninety Seven Employee Stock Purchase Plan [Member] Amended And Restated Nineteen Ninety Seven Employee Stock Purchase Plan [Member] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Restricted Stock, Restricted Stock Units, and Performance-Based Stock Units Restricted Stock Restricted Stock Units And Performance Stock Units [Member] Restricted stock, restricted stock units and performance stock units. Restricted Stock Awards Restricted Stock [Member] Restricted Stock and Restricted Stock Unit Restricted Stock And Restricted Stock Unit [Member] Restricted stock and restricted stock unit. Performance-Based Stock Units Performance Stock Unit [Member] Performance stock unit. Stock Options Employee Stock Option [Member] Market-based Performance Stock Options Market-based Performance Stock Options [Member] Market-based Performance Stock Options [Member] Limited Partners' Capital Account [Line Items] Limited Partners' Capital Account [Line Items] Common stock, authorized shares (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized Number of shares available for future grant (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Options granted period Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Options vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Stock-based compensation expense Allocated Share-based Compensation Expense Aggregate intrinsic value of options exercised Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Unrecognized stock-based compensation expense Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options Unrecognized stock-based compensation expense, weighted average period Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Total fair value of other stock awards vested Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Unrecognized stock-based compensation expense Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options Weighted average fair value (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value Risk free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Earnings Per Share [Abstract] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Class B Common Stock Common Class B [Member] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Numerator: Net Income (Loss) Available to Common Stockholders, Diluted [Abstract] Net loss attributable to common stockholders Net Income (Loss) Attributable to Parent Number of shares outstanding, end of period: Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Common stock, outstanding shares (in shares) Common Stock, Shares, Outstanding Unvested restricted stock (in shares) Weighted Average Number of Shares, Contingently Issuable Effect of weighted average shares outstanding (in shares) Weighted Average Number of Shares Issued, Basic Basic and diluted weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic and Diluted Antidilutive potentially issuable shares (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Fair Value Disclosures [Abstract] FAIR VALUE OF FINANCIAL INSTRUMENTS Fair Value Disclosures [Text Block] Income Statement [Abstract] Revenues Revenues Operating expenses: Costs and Expenses [Abstract] Cost of operations Cost of Goods and Services Sold General and administration General and Administrative Expense Depreciation and amortization Depreciation, Depletion and Amortization Total operating expenses Costs and Expenses Operating income Operating Income (Loss) Other expense (income): Nonoperating Income (Expense) [Abstract] Interest income Interest Income, Other Interest expense Interest Expense Loss (gain) on debt extinguishment Gain (Loss) on Extinguishment of Debt Other income Other Nonoperating Income Other expense, net Nonoperating Income (Expense) Loss before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Provision (benefit) for income taxes Income Tax Expense (Benefit) Net loss Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Less: Net loss attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Net loss attributable to common stockholders Basic and diluted earnings per share attributable to common stockholders: Earnings Per Share, Basic [Abstract] Basic and diluted earnings per common share (in USD per share) Earnings Per Share, Basic and Diluted EARNINGS PER SHARE Earnings Per Share [Text Block] STOCKHOLDERS' EQUITY Shareholders' Equity and Share-based Payments [Text Block] Accounting Changes and Error Corrections [Abstract] ACCOUNTING CHANGES New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Asset Retirement Obligation Disclosure [Abstract] Summary of Changes to Accrued Capping, Closure and Post-Closure Liabilities Schedule of Change in Asset Retirement Obligation [Table Text Block] Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Commitments and Contingencies Disclosure [Abstract] Loss Contingencies [Table] Loss Contingencies [Table] Environmental Exit Cost by Property [Axis] Environmental Exit Cost by Property [Axis] Environmental Exit Costs, Name of Property [Domain] Environmental Exit Costs, Name of Property [Domain] Town of Southbridge, Massachusetts Landfill Town of Southbridge, Massachusetts Landfill [Member] Town of Southbridge, Massachusetts Landfill [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] 21E Settlement and Water System Construction Funding Agreement 21E Settlement and Water System Construction Funding Agreement [Member] 21E Settlement and Water System Construction Funding Agreement [Member] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Bonds Bonds [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] MADEP and Casella Waste System Massachusetts Department of Environmental Protection (MADEP) and Casella Waste Systems [Member] Massachusetts Department of Environmental Protection (MADEP) and Casella Waste Systems [Member] Litigation Case [Axis] Litigation Case [Axis] Litigation Case [Domain] Litigation Case [Domain] Notice of Intent to Sue under the Resource Conservation and Recovery Act Notice of Intent to Sue under the Resource Conservation and Recovery Act [Member] Notice of Intent to Sue under the Resource Conservation and Recovery Act [Member] Environmental Remediation Site [Axis] Environmental Remediation Site [Axis] Environmental Remediation Site [Domain] Environmental Remediation Site [Domain] Potsdam Environmental Remediation Liability Potsdam Environmental Liability [Member] Potsdam environmental liability. Loss Contingencies [Line Items] Loss Contingencies [Line Items] Investigative expenditure incurred, expect recovery amount Environmental Exist Costs, Asset Recovery Environmental Exist Costs, Asset Recovery Shared costs Loss Contingency, Estimate of Possible Loss Bond period Debt Instrument, Term Aggregate principal amount Debt Instrument, Face Amount Scrap yard and solid waste transfer station (in acres) Scrap Yard And Solid Waste Transfer Station Acreage of scrap yard owned by WSI. Estimate of total undiscounted costs associated with implementing the preferred remedies Environmental Exit Costs, Anticipated Cost Remediation activities, participant share percentage Percentage Participation in Onsite Remediation Activities Percentage participation in onsite remediation activities. Risk free interest rate Accrual for Environmental Loss Contingencies, Discount Rate Accrual for Environmental Loss Contingencies Accrual for Environmental Loss Contingencies Document And Entity Information [Abstract] Document and entity information. Document Information [Table] Document Information [Table] Document Information [Line Items] Document Information [Line Items] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Trading Symbol Trading Symbol Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Marketable Securities Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Interest Rate Swaps Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] Beginning balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Other comprehensive income (loss) before reclassifications Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Amounts reclassified from accumulated other comprehensive income (loss) Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Other comprehensive loss, net of tax Other Comprehensive Income (Loss), Net of Tax Ending balance Business Combinations [Abstract] Revenue Business Acquisition, Pro Forma Revenue Operating income Business Acquisitions Pro Forma Operating Income Loss The pro forma operating income for the period as if the business combination or combinations had been completed at the beginning of the period. Net loss attributable to common stockholders Business Acquisition, Pro Forma Net Income (Loss) Basic earnings per share attributable to common stockholders (in USD per share) Business Acquisition, Pro Forma Earnings Per Share, Basic Basic weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic BUSINESS COMBINATIONS Business Combination Disclosure [Text Block] Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest rate swaps Interest Rate Swap [Member] Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest [Member] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Member] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Loss before income taxes Net loss Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Performance-based stock units, percentage of attainment level Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage Performance-based stock units Additional Shares Issued Maximum Attainment Level Additional shares of Class A Common Stock potentially issuable if maximum attainment levels are met. Organization, Consolidation and Presentation of Financial Statements [Abstract] Number of regional operating segments Number of Regional Operating Segments Number of Regional Operating Segments Debt Disclosure [Abstract] LONG-TERM DEBT Debt Disclosure [Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Activity and Balances Related to Goodwill by Operating Segment Schedule of Goodwill [Table Text Block] Summary of Intangible Assets by Intangible Asset Type Schedule of Finite-Lived Intangible Assets [Table Text Block] Summary of Intangible Amortization Expense Estimated Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Class of Stock [Line Items] Class of Stock [Line Items] Stock Options Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Beginning balance, outstanding (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period Ending balance, outstanding (in shares) Exercisable at end of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Unvested at end of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Beginning balance, Outstanding (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Granted (in USD per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Exercised (in USD per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Forfeited (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price Ending balance, Outstanding (in USD per share) Exercisable at end of period (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Unvested at end of period (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract] Weighted Average Remaining Contractual Term, Outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Weighted Average Remaining Contractual Term, Exercisable Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Weighted Average Remaining Contractual Term, Unvested Share-based Compensation Arrangement by Share-based Payment Award, Options, Unvested, Weighted Average Remaining Contractual Term Share-based Compensation Arrangement by Share-based Payment Award, Options, Unvested, Weighted Average Remaining Contractual Term Aggregate Intrinsic Value, Outstanding at end of period Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Aggregate Intrinsic Value, Exercisable at end of period Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Aggregate Intrinsic Value, Unvested at end of period Share-based Compensation Arrangement by Share-based Payment Award, Options, Unvested, Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Unvested, Aggregate Intrinsic Value Percentage of vesting of share-based compensation awards Issuance of additional shares (in shares) Common Stock, Capital Shares Reserved for Future Issuance Summary of Numerator and Denominators Used in Computation of Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Quoted Prices in Active Markets for Identical Assets (Level 1) Fair Value, Inputs, Level 1 [Member] Significant Other Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Significant Unobservable Inputs (Level 3) Fair Value, Inputs, Level 3 [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Recurring Fair Value, Measurements, Recurring [Member] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Restricted investments - landfill closure Landfill [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Assets: Assets [Abstract] Interest rate derivatives Derivative Asset Restricted assets Restricted Cash and Investments, Noncurrent Liabilities: Liabilities [Abstract] Interest rate derivative Interest Rate Derivative Liabilities, at Fair Value Schedule of Goodwill [Table] Schedule of Goodwill [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Eastern Eastern Region [Member] Eastern region. Western Western Region [Member] Western region. Recycling Recycling [Member] Recycling [Member] Other Other Segments [Member] Goodwill [Line Items] Goodwill [Line Items] Goodwill [Roll Forward] Goodwill [Roll Forward] Goodwill, beginning balance Goodwill Acquisitions Goodwill, Acquired During Period Goodwill, ending balance Intangible amortization expenses Amortization of Intangible Assets Statement of Comprehensive Income [Abstract] Net loss Other comprehensive income (loss), before tax: Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract] Hedging activity: Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax [Abstract] Interest rate swap settlements Other Comprehensive Income (Loss), Settlement on Derivatives, before Tax Other Comprehensive Income (Loss), Settlement on Derivatives, before Tax Interest rate swap amounts reclassified into interest expense Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax Unrealized loss resulting from changes in fair value of derivative instruments Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax Other comprehensive loss Other Comprehensive Income (Loss), before Tax Income tax expense related to items of other comprehensive loss Other Comprehensive Income (Loss), Tax Comprehensive loss Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Less: Comprehensive loss attributable to noncontrolling interests Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Comprehensive loss attributable to common stockholders Comprehensive Income (Loss), Net of Tax, Attributable to Parent Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Common Stock Common Stock [Member] Additional Paid-In Capital Additional Paid-in Capital [Member] Accumulated Deficit Retained Earnings [Member] Comprehensive Loss AOCI Attributable to Parent [Member] Noncontrolling Interests Noncontrolling Interest [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance (in shares) Net loss Other comprehensive loss Issuances of Class A common stock Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Issuances of Class A common stock (in shares) Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Stock-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Balance (in shares) Summary of Components of Long-Term Debt and Capital Leases by Debt Instrument Schedule of Debt [Table Text Block] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Transfer Stations Acquisition Transfer Stations Acquisition [Member] Transfer Stations Acquisition [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Purchase Price: Business Combination, Consideration Transferred [Abstract] Cash paid for acquisitions Payments to Acquire Businesses, Gross Holdback Business Combination, Consideration Transferred, Liabilities Incurred Total Business Combination, Consideration Transferred Allocated as follows: Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract] Equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Equipment Intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Other liabilities, net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Fair value of assets acquired and liabilities assumed Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Excess purchase price allocated to goodwill Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Subsequent Events Subsequent Events, Policy [Policy Text Block] Accounting standards that are not yet adopted New Accounting Pronouncements, Policy [Policy Text Block] Accrued Final Capping, Closure and Post Closure Asset Retirement Obligations, Policy [Policy Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Term Loan B Facility due October 2023; bearing interest at LIBOR plus 3.00% Term Facility due October 2023 (Term Loan B Facility) [Member] Term Facility due October 2023 (Term Loan B Facility) [Member] Revolving Credit Facility Senior Secured Asset Based Revolving Credit Facility Due Two Thousand And Twenty [Member] Senior Secured Asset Based Revolving Credit Facility Due Two Thousand And Twenty [Member] Secured Debt Secured Debt [Member] New York State Environmental Facilities Corporation Solid Waste Disposal Revenue Bonds Series 2014 due December 2044 - fixed rate interest period through 2019; bearing interest at 3.75% Revenue Bonds Series Two Thousand Fourteen Due Two Thousand Forty Four [Member] Revenue Bonds Series Two Thousand Fourteen Due Two Thousand Forty Four [Member] New York State Environmental Facilities Corporation Solid Waste Disposal Revenue Bonds Series 2014R-2 due December 2044 - fixed rate interest period through 2026; bearing interest at 3.125% Revenue Bond Series Two Thousand Fourteen R Two Due Two Thousand Forty Four [Member] Revenue Bond Series Two Thousand Fourteen R Two Due Two Thousand Forty Four [Member] Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-3 due January 2025 - fixed rate interest period through 2025; bearing interest at 5.25% Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-3 (FAME Bonds 2005R-3) [Member] Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-3 (FAME Bonds 2005R-3) [Member] Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2015 due August 2035 - fixed rate interest period through 2025; bearing interest at 5.125% Revenue Bonds Series Two Thousand Fifteen Due Two Thousand Thirty Five [Member] Revenue Bonds Series Two Thousand Fifteen Due Two Thousand Thirty Five [Member] Vermont Economic Development Authority Solid Waste Disposal Long-Term Revenue Bonds Series 2013 due April 2036 - fixed rate interest period through 2018; bearing interest at 4.75% Long Term Revenue Bond Series Two Thousand Thirteen Due Two Thousand Thirty Six [Member] Long Term Revenue Bond Series Two Thousand Thirteen Due Two Thousand Thirty Six [Member] Business Finance Authority of the State of New Hampshire Solid Waste Disposal Revenue Bonds Series 2013 due April 2029 - fixed rate interest period through 2019; bearing interest at 4.00% Revenue Bond Series Two Thousand Thirteen Due Two Thousand Twenty Nine [Member] Revenue Bond Series Two Thousand Thirteen Due Two Thousand Twenty Nine [Member] Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-2 due January 2025 - fixed rate interest period through 2017; bore interest at 6.25% Revenue Bonds Series Two Thousand Five Rtwo Due Two Thousand Twenty Five [Member] Revenue Bonds Series Two Thousand Five Rtwo Due Two Thousand Twenty Five [Member] Finance Authority of Maine Solid Waste Disposal Revenue Bonds Series 2005R-1; letter of credit backed due January 2025 - bore interest at SIFMA Index Revenue Bonds Series Two Thousand Five Rone Due Two Thousand Twenty Five [Member] Revenue Bonds Series Two Thousand Five Rone Due Two Thousand Twenty Five [Member] Capital Lease Obligations Capital Lease Obligations [Member] Notes Payable Notes Payable [Member] Notes Payable [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Long-term debt and capital lease Debt and Capital Lease Obligations Less—unamortized discount and debt issuance costs Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Long-term debt and capital leases less unamortized discount and debt issuance costs Long-term Debt and Capital Lease Obligations, Including Current Maturities Less—current maturities of long-term debt Long-term Debt and Capital Lease Obligations, Current Non current portion of long term debt and capital lease obligation Long-term Debt and Capital Lease Obligations Unamortized discount Debt Instrument, Unamortized Discount Debt Covenant Terms [Axis] Debt Covenant Terms [Axis] Debt Covenant Terms [Axis] Debt Covenant Terms [Domain] Debt Covenant Terms [Domain] [Domain] for Debt Covenant Terms [Axis] Consolidated net leverage ratio of 3.75x or less Debt Instrument, Covenant Compliance, Consolidated Net Leverage Ratio [Member] Debt Instrument, Covenant Compliance, Consolidated Net Leverage Ratio [Member] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Credit Facility Revolving Credit Facility [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] LIBOR Floor London Interbank Offered Rate (LIBOR) Floor [Member] London Interbank Offered Rate (LIBOR) Floor [Member] Base Rate Base Rate [Member] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Cash Flow Hedging Cash Flow Hedging [Member] Interest Rate Derivative Interest Rate Contract [Member] Interest Rate Derivative - February 2021 Interest Rate Contract - February 2021 [Member] Interest Rate Contract - February 2021 [Member] Interest Rate Derivative - February 2022 Interest Rate Contract - February 2022 [Member] Interest Rate Contract - February 2022 [Member] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] Major Types of Debt and Equity Securities [Domain] Maine Bonds Maine Bonds [Member] Maine Bonds [Member] Line of Credit Line of Credit [Member] New York Bonds 2016 Unsecured Debt [Member] Senior Subordinated Notes Due 2019 Notes Senior Subordinated Notes Due Two Thousand Nineteen [Member] Senior Subordinated Notes Due Two Thousand Nineteen [Member] Revolving Credit Facility due October 2021 Revolving Credit Facility due October 2021 [Member] Revolving Credit Facility due October 2021 [Member] Term Loan B Facility due October 2023; bearing interest at LIBOR plus 3.00% Term Loan Facility B, Repricing Amendment [Member] Term Loan Facility B, Repricing Amendment [Member] Variable Rate Bonds Variable Rate Bonds [Member] Variable Rate Bonds [Member] Revolving facility amount Line of Credit Facility, Maximum Borrowing Capacity Debt instrument variable rate basis Debt Instrument, Basis Spread on Variable Rate Decrease in applicable interest margin Debt Instrument, Increase (Decrease) in Basis Spread on Variable Rate Debt Instrument, Increase (Decrease) in Basis Spread on Variable Rate Net leverage ratio Debt Instrument, Covenant Compliance, Net Leverage Ratio Debt Instrument, Covenant Compliance, Net Leverage Ratio Carrying value of bonds Long-term Debt, Gross Debt instrument interest rate Debt Instrument, Interest Rate, Stated Percentage Gain (loss) on debt extinguishment Interest rate derivatives entered into Number of Interest Rate Derivatives Held Notional amount Derivative, Notional Amount Floor interest rate received Derivative, Basis Spread on Variable Rate Weighted average rate paid Derivative, Average Fixed Interest Rate Derivative asset fair value Derivative Asset, Fair Value, Gross Asset Derivative liability fair value Derivative Liability, Fair Value, Gross Liability Statement of Financial Position [Abstract] ASSETS CURRENT ASSETS: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Accounts receivable - trade, net of allowance for doubtful accounts $645 and $1,069, respectively Accounts Receivable, Net, Current Refundable income taxes Income Taxes Receivable, Current Prepaid expenses Prepaid Expense, Current Inventory Inventory, Gross Other current assets Other Assets, Current Total current assets Assets, Current Property, plant, and equipment, net of accumulated depreciation and amortization of $850,962 and $837,122, respectively Property, Plant and Equipment, Net Goodwill Intangible assets, net Finite-Lived Intangible Assets, Net Cost method investments Cost Method Investments Other non-current assets Other Assets, Noncurrent Total assets Assets LIABILITIES AND STOCKHOLDERS' DEFICIT Liabilities and Equity [Abstract] CURRENT LIABILITIES: Liabilities, Current [Abstract] Current maturities of long-term debt and capital leases Accounts payable Accounts Payable, Current Accrued payroll and related expenses Employee-related Liabilities, Current Accrued interest Interest Payable, Current Current accrued capping, closure and post-closure costs Accrued Capping, Closure, Post-closure and Environmental Costs Other accrued liabilities Other Accrued Liabilities, Current Total current liabilities Liabilities, Current Long-term debt and capital leases, less current portion Accrued capping, closure and post-closure costs, less current portion Accrued Capping, Closure, Post-closure and Environmental Costs, Noncurrent Deferred income taxes Deferred Income Tax Liabilities, Net Other long-term liabilities Other Liabilities, Noncurrent COMMITMENTS AND CONTINGENCIES Commitments and Contingencies STOCKHOLDERS' DEFICIT: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Casella Waste Systems, Inc. stockholders' deficit Stockholders' Equity Attributable to Parent [Abstract] Common stock Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Accumulated deficit Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total Casella Waste Systems, Inc. stockholders' deficit Stockholders' Equity Attributable to Parent Noncontrolling interests Stockholders' Equity Attributable to Noncontrolling Interest Total stockholders' deficit Total liabilities and stockholders' deficit Liabilities and Equity Summary of Purchase Price Paid for Acquisitions Schedule of Business Acquisitions, by Acquisition [Table Text Block] Schedule of Unaudited Pro forma Combined Information Business Acquisition, Pro Forma Information [Table Text Block] Segment Reporting [Abstract] Summary of Financial Information by Reportable Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Summary of Revenues Attributable to Services Provided by Company Revenue from External Customers by Products and Services [Table Text Block] Summary of Stock Option Activity Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] Summary of Restricted Stock, Restricted Stock Unit and Performance-based Stock Unit Activity Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block] Summary of Changes in Balances of Each Component of Accumulated Other Comprehensive Loss Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Summary of Reclassifications Out of Accumulated Other Comprehensive Loss Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] BASIS OF PRESENTATION Business Description and Basis of Presentation [Text Block] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments Operating Segments [Member] Eliminations Consolidation, Eliminations [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Inter-Company Revenues Inter-Company Revenues Inter-Company Revenues Operating income (loss) Total assets Restricted Stock, Restricted Stock Units, and Performance-Based Stock Units Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Outstanding at beginning of period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Class A Common Stock Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Outstanding at end of period Expected to vest at end of period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Unvested, Number Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Unvested, Number Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Outstanding at beginning of period (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Class A Common Stock Vested (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Forfeited (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Outstanding at end of period (in USD per share) Expected to vest at end of period (in USD per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Unvested, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Unvested, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract] Weighted Average Remaining Contractual Term, Outstanding Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms Weighted Average Remaining Contractual Term, Expected to vest Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Remaining Contractual Term Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Remaining Contractual Term Aggregate Intrinsic Value, Outstanding at end of period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding Aggregate Intrinsic Value, Expected to vest at end of period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Aggregate Intrinsic Value GOODWILL AND INTANGIBLE ASSETS Goodwill and Intangible Assets Disclosure [Text Block] Estimated Future Amortization Expense, For the fiscal year ending December 31, 2017 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months Estimated Future Amortization Expense, For the fiscal year ending December 31, 2018 Finite-Lived Intangible Assets, Amortization Expense, Year Two Estimated Future Amortization Expense, For the fiscal year ending December 31, 2019 Finite-Lived Intangible Assets, Amortization Expense, Year Three Estimated Future Amortization Expense, For the fiscal year ending December 31, 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Four Estimated Future Amortization Expense, For the fiscal year ending December 31, 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Five Estimated Future Amortization Expense, Thereafter Finite-Lived Intangible Assets, Amortization Expense, after Year Five Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Fair Value Estimate of Fair Value Measurement [Member] Carrying Value Reported Value Measurement [Member] Fixed Rate Bonds Fixed Rate Bonds [Member] Fixed rate bonds. Fair value of fixed rate debt Debt Instrument, Fair Value Disclosure Carrying value of revolver debt Lines of Credit, Fair Value Disclosure Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] Beginning balance Asset Retirement Obligation Obligations incurred Asset Retirement Obligation, Liabilities Incurred Accretion expense Asset Retirement Obligation, Accretion Expense Obligations settled Asset Retirement Obligation, Liabilities Settled Ending balance Description of Recent Accounting Standards Updates ("ASU") Not Yet Adopted Schedule of Recent Accounting Pronouncements Not Yet Adopted [Table Text Block] Schedule of Recent Accounting Pronouncements Not Yet Adopted . ACCRUED FINAL CAPPING, CLOSURE AND POST CLOSURE Asset Retirement Obligation Disclosure [Text Block] COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] Revenue from External Customers by Products and Services [Table] Revenue from External Customers by Products and Services [Table] Products and Services [Axis] Products and Services [Axis] Products and Services [Domain] Products and Services [Domain] Collection Solid Waste Operations Collection [Member] Solid Waste Operations Collection [Member] Disposal Solid Waste Operations Disposal [Member] Solid Waste Operations Disposal [Member] Power generation Solid Waste Operations Power Generation [Member] Solid Waste Operations Power Generation [Member] Processing Solid Waste Operations Processing [Member] Solid Waste Operations Processing [Member] Solid waste operations Solid Waste Operations [Member] Solid waste operations. Organics Organics [Member] Organics. Customer solutions Customer Solutions [Member] Customer solutions. Revenue from External Customer [Line Items] Revenue from External Customer [Line Items] Accounts receivable - trade, allowance for doubtful accounts Allowance for Doubtful Accounts Receivable, Current Property, plant and equipment, accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Common stock, par value (in USD per share) Common Stock, Par or Stated Value Per Share Common stock, authorized shares (in shares) Common Stock, Shares Authorized Common stock, issued shares (in shares) Common Stock, Shares, Issued Common stock, votes (in votes per share) Common Stock, Votes Per Share Common Stock, Votes Per Share Statement of Cash Flows [Abstract] Cash Flows from Operating Activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income (loss) to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depletion of landfill operating lease obligations Depletion Of Landfill Operating Lease Obligations This element represents the noncash expense charged against earnings to recognize the depletion of landfill operating lease obligations. Interest accretion on landfill and environmental remediation liabilities Accretion Expense, Including Asset Retirement Obligations Amortization of debt issuance costs and discount on long-term debt Amortization of Debt Issuance Costs and Discounts Stock-based compensation Share-based Compensation Gain on sale of property and equipment Gain (Loss) on Disposition of Property Plant Equipment Deferred income taxes Deferred Income Tax Expense (Benefit) Changes in assets and liabilities, net of effects of acquisitions and divestitures: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable Increase (Decrease) in Accounts Receivable Accounts payable Increase (Decrease) in Accounts Payable Prepaid expenses, inventories and other assets Increase (Decrease) in Prepaid Expense and Other Assets Accrued expenses and other liabilities Increase (Decrease) in Other Accounts Payable and Accrued Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash Flows from Investing Activities: Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Acquisitions, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Acquisition related additions to property, plant and equipment Payments To Acquire Acquisition Related Property Plant And Equipment The cash outflow associated with the acquisition of long-lived, physical assets that are the direct result of an acquisition that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets. Additions to property, plant and equipment Payments to Acquire Property, Plant, and Equipment Payments on landfill operating lease contracts Payments For Landfill Operating Lease The cash outflow associated with landfill operating agreements consisting of up-front or one-time payments, future minimum rental payments, including success/expansion fees, other direct costs and capping, closure and post closure costs. Proceeds from sale of property and equipment Proceeds from Sale of Property, Plant, and Equipment Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Cash Flows from Financing Activities: Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Proceeds from long-term borrowings Proceeds from Issuance of Long-term Debt and Capital Securities, Net Principal payments on long-term debt Repayments of Long-term Debt, Long-term Capital Lease Obligations, and Capital Securities Payments of debt issuance costs Payments of Debt Issuance Costs Proceeds from the exercise of share based awards Proceeds from Issuance of Shares under Incentive and Share-based Compensation Plans, Including Stock Options Change in restricted cash Proceeds from (Repayments of) Restricted Cash, Financing Activities Net cash (used in) provided by financing activities Net Cash Provided by (Used in) Financing Activities Net decrease in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Cash paid during the period for: Supplemental Cash Flow Information [Abstract] Interest Interest Paid, Net Income taxes, net of refunds Income Taxes Paid, Net Solid Waste Collection Solid Waste Collection Business [Member] Solid Waste Collection Business [Member] Number of transfer stations acquired Number of Businesses Acquired Debt instrument stated percentage Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Covenants Not-to-Compete Noncompete Agreements [Member] Client Lists Customer Lists [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Intangible assets Finite-Lived Intangible Assets, Gross Less accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Intangible assets, net SEGMENT REPORTING Segment Reporting Disclosure [Text Block]