Condensed Consolidating Financial Statements - Condensed Consolidating Statements of Operations (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Condensed Income Statements, Captions [Line Items]
Operating revenues	$ 3,360	$ 3,602	$ 9,715	$ 10,559
Costs and expenses	2,759	3,056	8,172	9,012
Income from operations	601	546	1,543	1,547
Other income (expense):
Interest expense, net	(95)	(116)	(294)	(352)
Loss on early extinguishment of debt			(552)
Other, net	(10)	(16)	(34)	(43)
Total other income (expense)	(105)	(132)	(880)	(395)
Income (loss) before income taxes	496	414	663	1,152
Provision for (benefit from) income taxes	159	133	184	412
Consolidated net income (loss)	337	281	479	740
Less: Net income (loss) attributable to noncontrolling interests	2	11	(1)	32
Net income (loss) attributable to Waste Management, Inc.	335	270	480	708
Eliminations [Member]
Other income (expense):
Equity in earnings of subsidiaries, net of taxes	(759)	(653)	(1,900)	(1,715)
Total other income (expense)	(759)	(653)	(1,900)	(1,715)
Income (loss) before income taxes	(759)	(653)	(1,900)	(1,715)
Consolidated net income (loss)	(759)	(653)	(1,900)	(1,715)
Net income (loss) attributable to Waste Management, Inc.	(759)	(653)	(1,900)	(1,715)
WM [Member]
Other income (expense):
Interest expense, net	(72)	(89)	(226)	(263)
Loss on early extinguishment of debt			(500)
Equity in earnings of subsidiaries, net of taxes	378	324	929	867
Total other income (expense)	306	235	203	604
Income (loss) before income taxes	306	235	203	604
Provision for (benefit from) income taxes	(29)	(35)	(277)	(104)
Consolidated net income (loss)	335	270	480	708
Net income (loss) attributable to Waste Management, Inc.	335	270	480	708
WM Holdings [Member]
Condensed Income Statements, Captions [Line Items]
Costs and expenses				(34)
Income from operations				34
Other income (expense):
Interest expense, net	(5)	(8)	(17)	(24)
Loss on early extinguishment of debt			(52)
Equity in earnings of subsidiaries, net of taxes	381	329	971	848
Total other income (expense)	376	321	902	824
Income (loss) before income taxes	376	321	902	858
Provision for (benefit from) income taxes	(2)	(3)	(27)	(9)
Consolidated net income (loss)	378	324	929	867
Net income (loss) attributable to Waste Management, Inc.	378	324	929	867
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Operating revenues	3,360	3,602	9,715	10,559
Costs and expenses	2,759	3,056	8,172	9,046
Income from operations	601	546	1,543	1,513
Other income (expense):
Interest expense, net	(18)	(19)	(51)	(65)
Other, net	(10)	(16)	(34)	(43)
Total other income (expense)	(28)	(35)	(85)	(108)
Income (loss) before income taxes	573	511	1,458	1,405
Provision for (benefit from) income taxes	190	171	488	525
Consolidated net income (loss)	383	340	970	880
Less: Net income (loss) attributable to noncontrolling interests	2	11	(1)	32
Net income (loss) attributable to Waste Management, Inc.	$ 381	$ 329	$ 971	$ 848