Condensed Consolidating Financial Statements (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Condensed Consolidating Statements of Comprehensive Income
Comprehensive income	$ 176	$ 252	$ 393	$ 475
Less: Comprehensive income attributable to noncontrolling interests	11	13	23	23
Comprehensive income attributable to Waste Management, Inc.	165	239	370	452
WM [Member]
Condensed Consolidating Statements of Comprehensive Income
Comprehensive income	190	231	366	421
Comprehensive income attributable to Waste Management, Inc.	190	231	366	421
WM Holdings [Member]
Condensed Consolidating Statements of Comprehensive Income
Comprehensive income	262	290	486	527
Comprehensive income attributable to Waste Management, Inc.	262	290	486	527
Non-Guarantor Subsidiaries [Member]
Condensed Consolidating Statements of Comprehensive Income
Comprehensive income	253	316	523	591
Less: Comprehensive income attributable to noncontrolling interests	11	13	23	23
Comprehensive income attributable to Waste Management, Inc.	242	303	500	568
Eliminations [Member]
Condensed Consolidating Statements of Comprehensive Income
Comprehensive income	(529)	(585)	(982)	(1,064)
Comprehensive income attributable to Waste Management, Inc.	$ (529)	$ (585)	$ (982)	$ (1,064)

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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