Condensed Consolidating Financial Statements (Details 1) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Condensed Consolidating Statements of Operations
Operating revenues	$ 3,522	$ 3,235	$ 9,972	$ 9,328
Costs and expenses	2,979	2,691	8,496	7,786
Income from operations	543	544	1,476	1,542
Other income (expense):
Interest income (expense)	(117)	(125)	(352)	(351)
Equity in earnings of subsidiaries, net of taxes	0	0	0	0
Other, net	(5)	(8)	(16)	(14)
Total other income (expense)	(122)	(133)	(368)	(365)
Income before income taxes	421	411	1,108	1,177
Provision for (benefit from) income taxes	136	153	377	469
Consolidated net income	285	258	731	708
Less: Net income attributable to noncontrolling interests	13	14	36	36
Net income attributable to Waste Management, Inc.	272	244	695	672
WM [Member]
Condensed Consolidating Statements of Operations
Operating revenues	0	0	0	0
Costs and expenses	0	0	0	0
Income from operations	0	0	0	0
Other income (expense):
Interest income (expense)	(85)	(88)	(256)	(241)
Equity in earnings of subsidiaries, net of taxes	323	298	850	819
Other, net	0	0	0	0
Total other income (expense)	238	210	594	578
Income before income taxes	238	210	594	578
Provision for (benefit from) income taxes	(34)	(34)	(101)	(94)
Consolidated net income	272	244	695	672
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Waste Management, Inc.	272	244	695	672
WM Holdings [Member]
Condensed Consolidating Statements of Operations
Operating revenues	0	0	0	0
Costs and expenses	0	0	0	0
Income from operations	0	0	0	0
Other income (expense):
Interest income (expense)	(8)	(9)	(25)	(28)
Equity in earnings of subsidiaries, net of taxes	328	303	865	836
Other, net	0	0	0	0
Total other income (expense)	320	294	840	808
Income before income taxes	320	294	840	808
Provision for (benefit from) income taxes	(3)	(4)	(10)	(11)
Consolidated net income	323	298	850	819
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Waste Management, Inc.	323	298	850	819
Non-Guarantor Subsidiaries [Member]
Condensed Consolidating Statements of Operations
Operating revenues	3,522	3,235	9,972	9,328
Costs and expenses	2,979	2,691	8,496	7,786
Income from operations	543	544	1,476	1,542
Other income (expense):
Interest income (expense)	(24)	(28)	(71)	(82)
Equity in earnings of subsidiaries, net of taxes	0	0	0	0
Other, net	(5)	(8)	(16)	(14)
Total other income (expense)	(29)	(36)	(87)	(96)
Income before income taxes	514	508	1,389	1,446
Provision for (benefit from) income taxes	173	191	488	574
Consolidated net income	341	317	901	872
Less: Net income attributable to noncontrolling interests	13	14	36	36
Net income attributable to Waste Management, Inc.	328	303	865	836
Eliminations [Member]
Condensed Consolidating Statements of Operations
Operating revenues	0	0	0	0
Costs and expenses	0	0	0	0
Income from operations	0	0	0	0
Other income (expense):
Interest income (expense)	0	0	0	0
Equity in earnings of subsidiaries, net of taxes	(651)	(601)	(1,715)	(1,655)
Other, net	0	0	0	0
Total other income (expense)	(651)	(601)	(1,715)	(1,655)
Income before income taxes	(651)	(601)	(1,715)	(1,655)
Provision for (benefit from) income taxes	0	0	0	0
Consolidated net income	(651)	(601)	(1,715)	(1,655)
Less: Net income attributable to noncontrolling interests	0	0	0	0
Net income attributable to Waste Management, Inc.	$ (651)	$ (601)	$ (1,715)	$ (1,655)