Condensed Consolidating Financial Statements - Balance Sheets (Detail) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 3,125	$ 3,561	$ 57
Other current assets	2,510	2,648
Total current assets	5,635	6,209
Property and equipment, net	12,900	12,893
Other assets	8,643	8,641
Total assets	27,178	27,743
Current liabilities:
Current portion of long-term debt	387	218
Accounts payable and other current liabilities	2,683	2,926
Total current liabilities	3,070	3,144
Long-term debt, less current portion	13,065	13,280
Other liabilities	4,298	4,249
Total liabilities	20,433	20,673
Equity:
Stockholders' equity	6,743	7,068
Noncontrolling interests	2	2
Total equity	6,745	7,070	$ 6,417	$ 6,276
Total liabilities and equity	27,178	27,743
Eliminations [Member]
Current assets:
Investments in affiliates	(53,671)	(52,894)
Advances to affiliates	(18,655)	(19,047)
Total assets	(72,326)	(71,941)
Current liabilities:
Due to affiliates	(25,664)	(26,690)
Total liabilities	(25,664)	(26,690)
Equity:
Stockholders' equity	(53,671)	(52,894)
Advances to affiliates	7,009	7,643
Total equity	(46,662)	(45,251)
Total liabilities and equity	(72,326)	(71,941)
WM [Member] | Reportable Legal Entities [Member]
Current assets:
Cash and cash equivalents	3,049	3,485
Other current assets	2	2
Total current assets	3,051	3,487
Investments in affiliates	26,650	26,221
Other assets	5	6
Total assets	29,706	29,714
Current liabilities:
Current portion of long-term debt	164	15
Accounts payable and other current liabilities	99	105
Total current liabilities	263	120
Long-term debt, less current portion	10,589	10,736
Due to affiliates	18,818	19,131
Other liabilities	2	4
Total liabilities	29,672	29,991
Equity:
Stockholders' equity	6,743	7,068
Advances to affiliates	(6,709)	(7,345)
Total equity	34	(277)
Total liabilities and equity	29,706	29,714
WM Holdings [Member] | Reportable Legal Entities [Member]
Current assets:
Other current assets	4	4
Total current assets	4	4
Investments in affiliates	27,021	26,673
Other assets	10	10
Total assets	27,035	26,687
Current liabilities:
Accounts payable and other current liabilities	3	7
Total current liabilities	3	7
Long-term debt, less current portion	248	248
Due to affiliates	137	214
Total liabilities	388	469
Equity:
Stockholders' equity	26,647	26,218
Total equity	26,647	26,218
Total liabilities and equity	27,035	26,687
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Current assets:
Cash and cash equivalents	76	76
Other current assets	2,504	2,642
Total current assets	2,580	2,718
Property and equipment, net	12,900	12,893
Advances to affiliates	18,655	19,047
Other assets	8,628	8,625
Total assets	42,763	43,283
Current liabilities:
Current portion of long-term debt	223	203
Accounts payable and other current liabilities	2,581	2,814
Total current liabilities	2,804	3,017
Long-term debt, less current portion	2,228	2,296
Due to affiliates	6,709	7,345
Other liabilities	4,296	4,245
Total liabilities	16,037	16,903
Equity:
Stockholders' equity	27,024	26,676
Advances to affiliates	(300)	(298)
Noncontrolling interests	2	2
Total equity	26,726	26,380
Total liabilities and equity	$ 42,763	$ 43,283