Condensed Consolidating Financial Statements - Condensed Consolidating Statements of Operations (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Condensed Income Statements, Captions [Line Items]
Operating revenues	$ 3,677	$ 3,425	$ 7,117	$ 6,601
Costs and expenses	3,004	2,814	5,886	5,482
Income from operations	673	611	1,231	1,119
Other income (expense):
Interest expense, net	(90)	(93)	(182)	(188)
Other, net	(13)	(59)	(45)	(76)
Total other income (expense)	(103)	(152)	(227)	(264)
Income before income taxes	570	459	1,004	855
Income tax expense (benefit)	209	173	346	313
Consolidated net income	361	286	658	542
Less: Net loss attributable to noncontrolling interests	(1)	(1)	(2)	(3)
Net income attributable to Waste Management, Inc.	362	287	660	545
Eliminations [Member]
Other income (expense):
Equity in earnings of subsidiaries, net of tax expense	(815)	(669)	(1,504)	(1,280)
Total other income (expense)	(815)	(669)	(1,504)	(1,280)
Income before income taxes	(815)	(669)	(1,504)	(1,280)
Consolidated net income	(815)	(669)	(1,504)	(1,280)
Net income attributable to Waste Management, Inc.	(815)	(669)	(1,504)	(1,280)
WM [Member] | Reportable Legal Entities [Member]
Other income (expense):
Interest expense, net	(74)	(76)	(148)	(150)
Equity in earnings of subsidiaries, net of tax expense	406	333	749	637
Other, net				(1)
Total other income (expense)	332	257	601	486
Income before income taxes	332	257	601	486
Income tax expense (benefit)	(30)	(30)	(59)	(59)
Consolidated net income	362	287	660	545
Net income attributable to Waste Management, Inc.	362	287	660	545
WM Holdings [Member] | Reportable Legal Entities [Member]
Other income (expense):
Interest expense, net	(5)	(5)	(10)	(10)
Equity in earnings of subsidiaries, net of tax expense	409	336	755	643
Total other income (expense)	404	331	745	633
Income before income taxes	404	331	745	633
Income tax expense (benefit)	(2)	(2)	(4)	(4)
Consolidated net income	406	333	749	637
Net income attributable to Waste Management, Inc.	406	333	749	637
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Condensed Income Statements, Captions [Line Items]
Operating revenues	3,677	3,425	7,117	6,601
Costs and expenses	3,004	2,814	5,886	5,482
Income from operations	673	611	1,231	1,119
Other income (expense):
Interest expense, net	(11)	(12)	(24)	(28)
Other, net	(13)	(59)	(45)	(75)
Total other income (expense)	(24)	(71)	(69)	(103)
Income before income taxes	649	540	1,162	1,016
Income tax expense (benefit)	241	205	409	376
Consolidated net income	408	335	753	640
Less: Net loss attributable to noncontrolling interests	(1)	(1)	(2)	(3)
Net income attributable to Waste Management, Inc.	$ 409	$ 336	$ 755	$ 643