Amount recognized as an operating expense or loss during the period to write-off the deferred costs associated with development projects no longer deemed viable. Abandoned Development Project Expense Deferred costs associated with development projects Development project charge The entire disclosure for the write-off of deferred costs associated with development projects no longer deemed viable. Abandoned Development Project Expense [Text Block] Development Project Charge Accounting Policies [Abstract] Accounting Policies [Abstract] Accounts Payable Current Accounts payable Accounts Receivable Net Current Accounts receivable - trade, net Accounts receivable - trade, net of allowance for doubtful accounts of $2,437 and $1,332 Accretion Expense Accretion expense Accretion Expense Including Asset Retirement Obligations Interest accretion on landfill and environmental remediation liabilities Accrual For Environmental Loss Contingencies Environmental remediation liability Accrual For Environmental Loss Contingencies Discount Rate Percentage of risk free interest rate Accrued Capping Closure Post Closure And Environmental Costs Current accrued capping, closure and post-closure costs Accrued Capping Closure Post Closure And Environmental Costs Noncurrent Accrued capping, closure and post-closure costs, less current portion Accumulated Deficit During Development Stage [Member] Accumulated Deficit [Member] Accumulated Depreciation Depletion And Amortization Property Plant And Equipment Property, plant and equipment, accumulated depreciation and amortization Accumulated Net Gain Loss From Designated Or Qualifying Cash Flow Hedges [Member] Commodity Hedges [Member] Accumulated Net Unrealized Investment Gain Loss [Member] Marketable Securities [Member] Accumulated Other Comprehensive Income Loss [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income Loss Net Of Tax Ending balance, January 31, 2014 Beginning balance, April 30, 2013 Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income Loss [Table] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income [Member] Accumulated Other Comprehensive Income (Loss) [Member] Acquisitions. Acquisitions [Member] Acquisition [Member] Additional Paid In Capital Common Stock Additional paid-in capital Additional Paid In Capital [Member] Additional Paid-In Capital [Member] Additional shares of Class A Common Stock that could be issued if maximum attainment levels are met. Additional Shares Issued Maximum Attainment Level Common stock additional issue Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value Stock-based compensation and related severance expense Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Adjustments to reconcile net loss to net cash provided by operating activities: Allocated Share Based Compensation Expense Stock-based compensation expense All Other Segments [Member] Other [Member] Allowance For Doubtful Accounts Receivable Current Accounts receivable - trade, allowance for doubtful accounts Amendment Flag Amendment Flag Amortization Of Debt Discount Premium Amortization of discount on second lien notes and senior subordinated notes Amortization Of Intangible Assets Intangible amortization expenses Anticipated remediation cost. Anticipated Remediation Cost Anticipated remediation costs Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount Number of antidilutive potentially issuable shares not included in the diluted earnings per share calculations due to loss from continuing operations Asset Retirement Obligation Ending balance Beginning balance Asset Retirement Obligation Accretion Expense Accretion expense Asset Retirement Obligation Cash Paid To Settle Payments Asset Retirement Obligation Disclosure [Abstract] Asset Retirement Obligation Disclosure [Abstract] Asset Retirement Obligation Disclosure [Text Block] Accrued Capping, Closure and Post Closure Asset Retirement Obligation Liabilities Incurred Obligations incurred Assets Total assets Total assets Assets [Abstract] ASSETS Assets: Assets Current Total current assets Total current assets Assets Current [Abstract] CURRENT ASSETS: Assets Noncurrent Total non-current assets Assets Of Disposal Group Including Discontinued Operation Current Current assets of discontinued operations Assets Of Disposal Group Including Discontinued Operation Noncurrent Non-current assets of discontinued operations Award Type [Axis] Award Type [Axis] Bbi waste industries and bestway disposal services. Bbi Waste Services And Bestway Disposal Services [Member] Bestway Disposal Services and BBI Waste Services [Member] Bbi waste services. Bbi Waste Services [Member] BBI Acquisition [Member] Bio fuels assets. Bio Fuels Assets [Member] Bio Fuels Assets [Member] Business Acquisition Acquiree [Domain] Business Acquisition, Acquiree [Domain] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition Effective Date Of Acquisition 1 Business acquisition date Business Acquisition Equity Interest Issued Or Issuable Value Assigned Business acquisition, stock value Common stock issued Business Acquisition Equity Interests Issued Or Issuable Number Of Shares Issued Business acquisition, shares Business Acquisition [Line Items] Business Acquisition [Line Items] Business Acquisition Percentage Of Voting Interests Acquired Membership interest acquired The pro forma basic and diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period. Business Acquisition Pro Forma Earnings Per Share Basic And Diluted Basic and diluted loss per common share attributable to common stockholders Business Acquisition Pro Forma Information [Text Block] Schedule of Unaudited Proforma Combined Financial Information Business Acquisitions Pro Forma Net Income Loss Net loss attributable to common stockholders The pro forma operating income for the period as if the business combination or combinations had been completed at the beginning of the period. Business Acquisitions Pro Forma Operating Income Loss Operating (loss) income Business Acquisitions Pro Forma Revenue Revenue Business Acquisition [Table] Business Acquisition [Table] Business Acquisition [Table] Business Combination Consideration Transferred 1 Total consideration Business Combination Consideration Transferred Liabilities Incurred Business acquisition, hold backs to sellers Business Combination Consideration Transferred Other 1 Business acquisition, advanced customer billings Other non-cash consideration Business Combination Contingent Consideration Arrangements Range Of Outcomes Value High Business combination consideration transferred contingent consideration, upper limit Business Combination Contingent Consideration Liability Business combination consideration transferred contingent consideration Business Combination Disclosure [Text Block] Business Acquisitions Business Combination Provisional Information Initial Accounting Incomplete Adjustment Intangibles Adjustment related to the December 5, 2012 Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Current Assets Current assets Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Current Liabilities Current liabilities Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Equipment Equipment Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Intangibles Intangible assets Business Combination Recognized Identifiable Assets Acquired Goodwill And Liabilities Assumed Net Total Business Combinations [Abstract] Business Combinations [Abstract] Business Combination Step Acquisition Equity Interest In Acquiree Fair Value 1 Price to purchase acquired assets prior to the acquisition date Business Combination Step Acquisition Equity Interest In Acquiree Remeasurement Gain Gain through loss from equity method investments Capital Lease Obligations Incurred Property, plant and equipment acquired through lease obligations Cash And Cash Equivalents At Carrying Value Cash and cash equivalents, end of period Cash and cash equivalents, beginning of period Cash and cash equivalents Cash And Cash Equivalents Period Increase Decrease Net increase (decrease) in cash and cash equivalents Net increase (decrease) in cash and cash equivalents Cash paid received during period. Cash Paid Received During Period [Abstract] Cash paid during the period for: Cash Provided By Used In Investing Activities Discontinued Operations Net cash provided by (used in) investing activities Cash Provided By Used In Operating Activities Discontinued Operations Net cash used in operating activities Class Of Stock [Domain] Class of Stock [Domain] Collection. Collection [Member] Collection [Member] Commitments And Contingencies COMMITMENTS AND CONTINGENCIES Commitments And Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Commodity Contract [Member] Commodity Contract [Member] Common Class A [Member] Class A Common Stock [Member] Common Class B [Member] Class B Common Stock [Member] Common Stock Capital Shares Reserved For Future Issuance Common stock, issued shares Common Stock Par Or Stated Value Per Share Common stock, par value Common Stock Shares Authorized Common stock, authorized shares Common Stock Shares Issued Common stock, issued shares Common Stock Shares Outstanding Balance (in shares) Balance (in shares) Common stock shares outstanding Common stock, outstanding shares Common Stock Value Common stock This element represents the number of votes per share that the holders are entitled to on common stock. Common Stock Votes Per Share Common stock, votes (in votes per share) Comprehensive Income Net Of Tax Comprehensive income (loss) attributable to common stockholders Comprehensive loss attributable to common stockholders Comprehensive Income Net Of Tax Attributable To Noncontrolling Interest Less: Comprehensive income (loss) attributable to noncontrolling interests Less: Comprehensive loss attributable to noncontrolling interests Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest Comprehensive income (loss) Comprehensive loss Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest [Abstract] Other comprehensive income (loss), net of taxes: Condensed Financial Statements Captions [Line Items] Condensed Financial Statements, Captions [Line Items] Condensed Financial Statements [Text Block] Subsidiary Guarantors Condition one. Condition One [Member] Condition One [Member] Consolidation Eliminations [Member] Elimination [Member] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Consolidation Policy [Text Block] Consolidation Contingencies And Commitments [Line Items] Contingencies And Commitments [Line Items] Contingencies And Commitments [Line Items] Contingencies And Commitments [Table] Contingencies And Commitments [Table] Contingencies And Commitments [Table] Cost And Equity Method Investments Disclosure [Text Block] Investments in Unconsolidated Entities Cost Method Investments Cost method investments Cost Of Goods And Services Sold Cost of operations Costs And Expenses Total operating expenses Total operating expenses Costs And Expenses [Abstract] Operating expenses: Current Fiscal Year End Date Current Fiscal Year End Date Current Income Tax Expense Benefit Provision for income taxes current Customer Lists [Member] Client Lists [Member] Customer solutions. Customer Solutions [Member] Customer Solutions [Member] Maximum annual capital expenditures ratio based on our senior credit facility. Debt Covenant Capital Expenditure To Depreciation Depletion And Landfill Amortization Expense Ratio Ratio of restricted capital expenditure Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Instrument Carrying Amount Carrying value of fixed rate debt Debt Instrument Covenant Description Debt Covenants, description Debt Instrument Face Amount Amount of refinancing 11% senior second lien notes due 2014 Debt Instrument Fair Value Fair value of fixed rate debt Debt Instrument Interest Rate Stated Percentage Debt instrument interest rate Stated percentage of senior subordinate notes Debt Instrument [Line Items] Debt Instrument [Line Items] Debt Instrument Maturity Date Maturity date Debt instrument maturity year. Debt Instrument Maturity Year Debt instrument maturity year Debt Instrument [Table] Schedule of Long-term Debt Instruments [Table] Deferred Income Tax Expense Benefit Deferred income taxes Provisions for income taxes deferred Deferred Tax Assets Net Current Deferred income taxes Deferred Tax Liabilities Goodwill And Intangible Assets Goodwill Deferred tax liability recorded through goodwill Deferred Tax Liabilities Noncurrent Deferred income taxes Denominator. Denominator [Abstract] Denominator: This element represents the noncash expense charged against earnings to recognize the depletion of landfill operating lease obligation. Depletion Of Landfill Operating Lease Obligations Depletion of landfill operating lease obligations Depreciation Depletion And Amortization Depreciation and amortization Derivative Contract Type [Domain] Derivative Contract [Domain] Derivative Instrument Risk [Axis] Derivative Instrument [Axis] Derivative Instruments Not Designated As Hedging Instruments Gain Loss Net Loss on derivative instruments Loss (gain) on derivative instruments Loss on derivative instruments Derivative Instruments Not Designated As Hedging Instruments Liability At Fair Value Interest rate derivatives Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax Loss on disposal of discontinued operations, net of tax Gain (loss) on disposal of discontinued operations, net Loss on disposal of discontinued operations (net of income tax provision of $0, $0, $0 and $0) Loss on disposal of discontinued operations, net of tax Amount of gain (loss), after tax expense or benefit and not previously recognized, resulting from the sale of a business component attributable to parent. Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax Attributable To Parent Loss on disposal of discontinued operations, net of tax Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax Per Basic And Diluted Share Loss on disposal of discontinued operations, net of tax Discontinued Operation Income Loss From Discontinued Operation Before Income Tax (Loss) income before income taxes Discontinued Operation Income Loss From Discontinued Operation During Phase Out Period Net Of Tax (Loss) income from discontinued operations (net of income tax provision of $0, $0, $0 and $0) Income (loss) from discontinued operations, net (Income) loss from discontinued operations, net of tax After tax income (loss) from operations of a business component (exclusive of any gain (loss) on disposal, or provision therefore) during the reporting period, until its disposal attributable to parent. Discontinued Operation Income Loss From Discontinued Operation During Phase Out Period Net Of Tax Attributable To Parent (Loss) income from discontinued operations, net of tax Discontinued Operation Income Loss From Discontinued Operation Net Of Tax Per Basic And Diluted Share (Loss) income from discontinued operations, net of tax Discontinued Operations And Disposal Groups [Abstract] Discontinued Operations and Disposal Groups [Abstract] Discontinued Operation Tax Effect Of Income Loss From Discontinued Operation During Phase Out Period Loss from discontinued operations, income tax provision Discontinued Operation Tax Effect Of Income Loss From Disposal Of Discontinued Operation Loss on disposal of discontinued operations, income tax provision Disposal Group Including Discontinued Operation Revenue Revenues Disposal Groups Including Discontinued Operations Disclosure [Text Block] Divestiture and Discontinued Operations Disposal. Disposal [Member] Disposal [Member] The write-off of costs associated with a financing initiative that is no longer being pursued, legal costs associated with a divestiture and costs associated with an acquisition. Divestiture Acquisition Financing Costs Expense from divestiture, acquisition and financing costs Divestitures [Line Items] Divestitures [Line Items] Divestitures [Line Items] Divestitures [Table] Divestitures [Table] Divestitures [Table] Document And Entity Information [Abstract] Document And Entity Information [Abstract] Document And Entity Information [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Document Fiscal Year Focus Document Fiscal Year Focus Document Information [Line Items] Document Information [Line Items] Document Period End Date Document Period End Date Document Type Document Type Earnings Per Share [Abstract] Earnings Per Share [Abstract] Earnings Per Share Basic And Diluted Net loss per common share Earnings Per Share Basic And Diluted [Abstract] Basic and diluted earnings per share: Earnings Per Share [Line Items] Earnings Per Share [Line Items] Earnings Per Share [Line Items] Earnings Per Share [Table] Earnings Per Share [Table] Earnings Per Share [Table] Earnings Per Share [Text Block] Earnings Per Share Eastern. Eastern [Member] Eastern Region [Member] Eastern region. Eastern Region [Member] Eastern Region [Member] Elimination. Elimination [Member] Eliminations [Member] Employee Related Liabilities Current Accrued payroll and related expenses Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition 1 Unrecognized stock-based compensation expense, weighted average period Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Share Based Awards Other Than Options Unrecognized stock-based compensation expense Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Stock Options Unrecognized stock-based compensation expense Employee stock purchase plan. Employee Stock Purchase Plan [Member] Employee Stock Purchase Plan [Member] Entities [Table] Entities [Table] Entity Central Index Key Entity Central Index Key Entity Common Stock Shares Outstanding Entity Common Stock, Shares Outstanding Entity [Domain] Entity [Domain] Entity Filer Category Entity Filer Category Entity Registrant Name Entity Registrant Name Environmental Remediation Expense Environmental remediation charge Environmental Remediation Site [Axis] Environmental Remediation Site [Axis] Environmental Remediation Site [Domain] Environmental Remediation Site [Domain] Equity [Abstract] Equity [Abstract] Equity Component [Domain] Equity Component [Domain] Equity method investment consideration. Equity Method Investment Consideration Total cash consideration Equity method investment disposal related working capital adjustment. Equity Method Investment Disposal Related Working Capital Adjustment Working capital adjustment Equity method investment final consideration. Equity Method Investment Final Consideration Gross cash proceeds Equity Method Investment Net Sales Proceeds Net cash proceeds Equity Method Investment Ownership Percentage Percentage of equity-method ownership interest Equity Method Investment Realized Gain Loss On Disposal Gain on sale of equity method investment (Gain) loss on sale of equity method investment Gain on sale of equity method investment Equity Method Investments Equity method investments