Condensed Consolidating Financial Statements - Condensed Consolidating Statements of Operations (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Condensed Income Statements, Captions [Line Items]
Operating revenues	$ 3,716	$ 3,548	$ 10,833	$ 10,149
Costs and expenses	3,015	2,988	8,901	8,470
Income from operations	701	560	1,932	1,679
Other income (expense):
Interest expense, net	(90)	(94)	(272)	(282)
Other, net	(8)	(9)	(53)	(85)
Total other income (expense)	(98)	(103)	(325)	(367)
Income before income taxes	603	457	1,607	1,312
Income tax expense (benefit)	215	153	561	466
Consolidated net income	388	304	1,046	846
Less: Net income (loss) attributable to noncontrolling interests	2	2		(1)
Net income attributable to Waste Management, Inc.	386	302	1,046	847
Eliminations [Member]
Other income (expense):
Equity in earnings of subsidiaries, net of tax	(867)	(701)	(2,371)	(1,981)
Total other income (expense)	(867)	(701)	(2,371)	(1,981)
Income before income taxes	(867)	(701)	(2,371)	(1,981)
Consolidated net income	(867)	(701)	(2,371)	(1,981)
Net income attributable to Waste Management, Inc.	(867)	(701)	(2,371)	(1,981)
WM [Member] | Reportable Legal Entities [Member]
Other income (expense):
Interest expense, net	(75)	(77)	(223)	(227)
Equity in earnings of subsidiaries, net of tax	432	349	1,181	986
Other, net				(1)
Total other income (expense)	357	272	958	758
Income before income taxes	357	272	958	758
Income tax expense (benefit)	(29)	(30)	(88)	(89)
Consolidated net income	386	302	1,046	847
Net income attributable to Waste Management, Inc.	386	302	1,046	847
WM Holdings [Member] | Reportable Legal Entities [Member]
Other income (expense):
Interest expense, net	(5)	(5)	(15)	(15)
Equity in earnings of subsidiaries, net of tax	435	352	1,190	995
Total other income (expense)	430	347	1,175	980
Income before income taxes	430	347	1,175	980
Income tax expense (benefit)	(2)	(2)	(6)	(6)
Consolidated net income	432	349	1,181	986
Net income attributable to Waste Management, Inc.	432	349	1,181	986
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Income Statements, Captions [Line Items]
Operating revenues	3,716	3,548	10,833	10,149
Costs and expenses	3,015	2,988	8,901	8,470
Income from operations	701	560	1,932	1,679
Other income (expense):
Interest expense, net	(10)	(12)	(34)	(40)
Other, net	(8)	(9)	(53)	(84)
Total other income (expense)	(18)	(21)	(87)	(124)
Income before income taxes	683	539	1,845	1,555
Income tax expense (benefit)	246	185	655	561
Consolidated net income	437	354	1,190	994
Less: Net income (loss) attributable to noncontrolling interests	2	2		(1)
Net income attributable to Waste Management, Inc.	$ 435	$ 352	$ 1,190	$ 995