Condensed Consolidating Financial Statements - Condensed Consolidating Statements of Operations (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Income Statements, Captions [Line Items]
Operating revenues	$ 3,246	$ 3,360	$ 3,315	$ 3,040	$ 3,437	$ 3,602	$ 3,561	$ 3,396	$ 12,961	$ 13,996	$ 13,983
Costs and expenses									10,916	11,697	12,904
Income from operations	502	601	502	440	752	546	532	469	2,045	2,299	1,079
Other income (expense):
Interest expense, net									(385)	(466)	(477)
Loss on early extinguishment of debt									(555)
Other, net									(45)	(82)	(108)
Total other income (expense)									(985)	(548)	(585)
Income before income taxes									1,060	1,751	494
Provision for (benefit from) income taxes									308	413	364
Consolidated net income	273	337	273	(131)	598	281	222	237	752	1,338	130
Less: Net income (loss) attributable to noncontrolling interests									(1)	40	32
Net income attributable to Waste Management, Inc.	$ 273	$ 335	$ 274	$ (129)	$ 590	$ 270	$ 210	$ 228	753	1,298	98
Eliminations [Member]
Other income (expense):
Equity in earnings of subsidiaries, net of taxes									(2,534)	(2,580)	(645)
Total other income (expense)									(2,534)	(2,580)	(645)
Income before income taxes									(2,534)	(2,580)	(645)
Consolidated net income									(2,534)	(2,580)	(645)
Net income attributable to Waste Management, Inc.									(2,534)	(2,580)	(645)
WM [Member]
Other income (expense):
Interest expense, net									(298)	(351)	(355)
Loss on early extinguishment of debt									(500)
Equity in earnings of subsidiaries, net of taxes									1,245	1,510	313
Total other income (expense)									447	1,159	(42)
Income before income taxes									447	1,159	(42)
Provision for (benefit from) income taxes									(306)	(139)	(140)
Consolidated net income									753	1,298	98
Net income attributable to Waste Management, Inc.									753	1,298	98
WM Holdings [Member]
Condensed Income Statements, Captions [Line Items]
Costs and expenses									(1)	(459)
Income from operations									1	459
Other income (expense):
Interest expense, net									(22)	(31)	(32)
Loss on early extinguishment of debt									(52)
Equity in earnings of subsidiaries, net of taxes									1,289	1,070	332
Total other income (expense)									1,215	1,039	300
Income before income taxes									1,216	1,498	300
Provision for (benefit from) income taxes									(29)	(12)	(13)
Consolidated net income									1,245	1,510	313
Net income attributable to Waste Management, Inc.									1,245	1,510	313
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Operating revenues									12,961	13,996	13,983
Costs and expenses									10,917	12,156	12,904
Income from operations									2,044	1,840	1,079
Other income (expense):
Interest expense, net									(65)	(84)	(90)
Loss on early extinguishment of debt									(3)
Other, net									(45)	(82)	(108)
Total other income (expense)									(113)	(166)	(198)
Income before income taxes									1,931	1,674	881
Provision for (benefit from) income taxes									643	564	517
Consolidated net income									1,288	1,110	364
Less: Net income (loss) attributable to noncontrolling interests									(1)	40	32
Net income attributable to Waste Management, Inc.									$ 1,289	$ 1,070	$ 332