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Quarterly Financial Data (Unaudited) - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		12 Months Ended			3 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Jun. 30, 2013	Jun. 30, 2014	Mar. 31, 2013	Sep. 30, 2013
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Positive (Negative) impact on diluted earnings per common share	$ (0.49)	$ (0.09)
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Pre-tax restructuring charges		67us-gaap_RestructuringCharges	82us-gaap_RestructuringCharges	18us-gaap_RestructuringCharges	67us-gaap_RestructuringCharges
Net pre-tax	364wm_PreTaxNetCharges
Positive (Negative) impact on diluted earnings per common share			515us-gaap_GainLossOnSaleOfBusiness
(Income) expense from divestitures			515us-gaap_GainLossOnDispositionOfAssets1	8us-gaap_GainLossOnDispositionOfAssets1
Goodwill impairments			10us-gaap_GoodwillImpairmentLoss	509us-gaap_GoodwillImpairmentLoss	4us-gaap_GoodwillImpairmentLoss
Waste-to-Energy Facility [Member]
Quarterly Financial Information [Line Items]
Positive (Negative) impact on diluted earnings per common share							$ (0.02)
Impairment charges				144		130
Puerto Rico [Member]
Quarterly Financial Information [Line Items]
Gain (loss) on sale of business								(25)
Income tax expense (benefit)								0
Tax charges incurred prior to divestment								32
Positive (Negative) impact on diluted earnings per common share								$ (0.12)
Restructuring Charges [Member]
Quarterly Financial Information [Line Items]
Positive (Negative) impact on diluted earnings per common share	$ (0.02)					$ (0.01)
Pre-tax restructuring charges	13					5
Restructuring and Acquisition Integration Charges [Member]
Quarterly Financial Information [Line Items]
Positive (Negative) impact on diluted earnings per common share									$ (0.01)
Pre-tax restructuring charges									8
Impairment of Cost Method Investments in Waste Diversion Technology Companies [Member]
Quarterly Financial Information [Line Items]
Impairment charge relating to decline in value of investment accounted under cost method	20
Recycling Operations [Member]
Quarterly Financial Information [Line Items]
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Litigation Reserves and Impairments Partially Offset by Gain on Sale [Member]
Quarterly Financial Information [Line Items]
Positive (Negative) impact on diluted earnings per common share		$ (0.05)
Net pre-tax		20
Impairment of Waste Processing Facility and Other Pretax Charges [Member]
Quarterly Financial Information [Line Items]
Positive (Negative) impact on diluted earnings per common share								$ (0.03)
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Waste Processing Facility [Member]
Quarterly Financial Information [Line Items]
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Wheelabrator [Member]
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Positive (Negative) impact on diluted earnings per common share	519		519
Goodwill impairments				483		483
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Quarterly Financial Information [Line Items]
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Eastern Canada Area [Member] \| Landfill [Member]
Quarterly Financial Information [Line Items]
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Partial Withdrawal from Underfunded Multi Employer Pension Plan and Restructuring [Member]
Quarterly Financial Information [Line Items]
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Other pre-tax charges										8
Changes in Bad Debt Expense [Member] \| Puerto Rico [Member]
Quarterly Financial Information [Line Items]
Positive (Negative) impact on diluted earnings per common share									$ (0.01)	$ 0.01
Year-end Landfill Adjustments and Risk Free Discount Rate Used to Measure Environmental Remediation Liabilities [Member]
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Positive (Negative) impact on diluted earnings per common share						$ 0.02
Impairment of Investment in Waste Diversion Technology Company and Goodwill [Member]
Quarterly Financial Information [Line Items]
Positive (Negative) impact on diluted earnings per common share									$ (0.03)
Impairment charges									15
Risk Free Discount Rate Used to Measure Environmental Remediation Liabilities [Member]
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Positive (Negative) impact on diluted earnings per common share							$ 0.01
Impairment and Loss on Divestiture [Member]
Quarterly Financial Information [Line Items]
Positive (Negative) impact on diluted earnings per common share										$ (0.02)
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Investment in Waste Diversion Technology Company [Member]
Quarterly Financial Information [Line Items]
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Oil and Gas Well [Member]
Quarterly Financial Information [Line Items]
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(Income) expense from divestitures										5
Waste Diversion Technology Company [Member]
Quarterly Financial Information [Line Items]
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Impairment of Goodwill Landfills Waste to Energy Facilities Recycling Assets and Other [Member]
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Net pre-tax						1,000
Recycling Assets [Member]
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