Condensed Consolidating Financial Statements - Condensed Consolidating Statements of Cash Flows (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:
Consolidated net income	$ 459	$ 432
Equity in earnings of subsidiaries, net of taxes	0
Other adjustments	680	690
Net cash provided by (used in) operating activities	1,139	1,122
Cash flows from investing activities:
Acquisitions of businesses, net of cash acquired	(26)	(210)
Capital expenditures	(474)	(501)
Proceeds from divestitures of businesses (net of cash divested) and other sales of assets	266	74
Net receipts from restricted trust and escrow accounts and other, net	(60)	(56)
Net cash provided by (used in) investing activities	(294)	(693)
Cash flows from financing activities:
New borrowings	1,500	461
Debt repayments	(1,925)	(658)
Cash dividends	(349)	(341)
Exercise of common stock options	31	98
Distributions paid to noncontrolling interests and other	(23)	(25)
(Increase) decrease in intercompany and investments, net	0
Net cash provided by (used in) financing activities	(766)	(465)
Effect of exchange rate changes on cash and cash equivalents	0	(4)
Increase (decrease) in cash and cash equivalents	79	(40)
Cash and cash equivalents at beginning of period	58	194
Cash and cash equivalents at end of period	137	154
Eliminations [Member]
Cash flows from operating activities:
Consolidated net income	(1,062)	(1,053)
Equity in earnings of subsidiaries, net of taxes	1,062	1,053
Other adjustments	0
Net cash provided by (used in) operating activities	0
Cash flows from investing activities:
Acquisitions of businesses, net of cash acquired	0
Capital expenditures	0
Proceeds from divestitures of businesses (net of cash divested) and other sales of assets	0
Net receipts from restricted trust and escrow accounts and other, net	0
Net cash provided by (used in) investing activities	0
Cash flows from financing activities:
New borrowings	0
Debt repayments	0
Cash dividends	0
Exercise of common stock options	0
Distributions paid to noncontrolling interests and other	0
(Increase) decrease in intercompany and investments, net	0
Net cash provided by (used in) financing activities	0
Effect of exchange rate changes on cash and cash equivalents	0
Increase (decrease) in cash and cash equivalents	0
Cash and cash equivalents at beginning of period	0
Cash and cash equivalents at end of period	0
WM [Member]
Cash flows from operating activities:
Consolidated net income	438	412
Equity in earnings of subsidiaries, net of taxes	(543)	(521)
Other adjustments	(39)	14
Net cash provided by (used in) operating activities	(144)	(95)
Cash flows from investing activities:
Acquisitions of businesses, net of cash acquired	0
Capital expenditures	0
Proceeds from divestitures of businesses (net of cash divested) and other sales of assets	0
Net receipts from restricted trust and escrow accounts and other, net	0
Net cash provided by (used in) investing activities	0
Cash flows from financing activities:
New borrowings	1,367	390
Debt repayments	(1,685)	(455)
Cash dividends	(349)	(341)
Exercise of common stock options	31	98
Distributions paid to noncontrolling interests and other	1	7
(Increase) decrease in intercompany and investments, net	779	386
Net cash provided by (used in) financing activities	144	85
Effect of exchange rate changes on cash and cash equivalents	0
Increase (decrease) in cash and cash equivalents	0	(10)
Cash and cash equivalents at beginning of period	0	60
Cash and cash equivalents at end of period	0	50
WM Holdings [Member]
Cash flows from operating activities:
Consolidated net income	543	521
Equity in earnings of subsidiaries, net of taxes	(519)	(532)
Other adjustments	0
Net cash provided by (used in) operating activities	24	(11)
Cash flows from investing activities:
Acquisitions of businesses, net of cash acquired	0
Capital expenditures	0
Proceeds from divestitures of businesses (net of cash divested) and other sales of assets	42
Net receipts from restricted trust and escrow accounts and other, net	0
Net cash provided by (used in) investing activities	42
Cash flows from financing activities:
New borrowings	0
Debt repayments	0
Cash dividends	0
Exercise of common stock options	0
Distributions paid to noncontrolling interests and other	0
(Increase) decrease in intercompany and investments, net	(66)	11
Net cash provided by (used in) financing activities	(66)	11
Effect of exchange rate changes on cash and cash equivalents	0
Increase (decrease) in cash and cash equivalents	0
Cash and cash equivalents at beginning of period	0
Cash and cash equivalents at end of period	0
Non-Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Consolidated net income	540	552
Equity in earnings of subsidiaries, net of taxes	0
Other adjustments	719	676
Net cash provided by (used in) operating activities	1,259	1,228
Cash flows from investing activities:
Acquisitions of businesses, net of cash acquired	(26)	(210)
Capital expenditures	(474)	(501)
Proceeds from divestitures of businesses (net of cash divested) and other sales of assets	224	74
Net receipts from restricted trust and escrow accounts and other, net	(60)	(56)
Net cash provided by (used in) investing activities	(336)	(693)
Cash flows from financing activities:
New borrowings	133	71
Debt repayments	(240)	(203)
Cash dividends	0
Exercise of common stock options	0
Distributions paid to noncontrolling interests and other	(24)	(32)
(Increase) decrease in intercompany and investments, net	(713)	(397)
Net cash provided by (used in) financing activities	(844)	(561)
Effect of exchange rate changes on cash and cash equivalents	0	(4)
Increase (decrease) in cash and cash equivalents	79	(30)
Cash and cash equivalents at beginning of period	58	134
Cash and cash equivalents at end of period	$ 137	$ 104