Condensed Consolidating Statements of Comprehensive Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Condensed Financial Statements, Captions [Line Items]
Comprehensive income	$ 260	$ 170	$ 653	$ 645
Less: Comprehensive income attributable to noncontrolling interests	9	13	32	36
Comprehensive income attributable to Waste Management, Inc.	251	157	621	609
WM [Member]
Condensed Financial Statements, Captions [Line Items]
Comprehensive income	215	246	581	667
Comprehensive income attributable to Waste Management, Inc.	215	246	581	667
WM Holdings [Member]
Condensed Financial Statements, Captions [Line Items]
Comprehensive income	269	323	755	850
Comprehensive income attributable to Waste Management, Inc.	269	323	755	850
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Comprehensive income	319	252	842	843
Less: Comprehensive income attributable to noncontrolling interests	9	13	32	36
Comprehensive income attributable to Waste Management, Inc.	310	239	810	807
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Comprehensive income	(543)	(651)	(1,525)	(1,715)
Comprehensive income attributable to Waste Management, Inc.	$ (543)	$ (651)	$ (1,525)	$ (1,715)

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

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The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to noncontrolling interests. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

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- Definition

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the economic entity, including both controlling (parent) and noncontrolling interests. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, including any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

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