Condensed Consolidating Financial Statements - Balance Sheets (Detail) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 57	$ 61	$ 52
Other current assets	2,431	2,584
Total current assets	2,488	2,645
Property and equipment, net	12,390	11,942
Other assets	8,495	8,063
Total assets	23,373	22,650
Current liabilities:
Current portion of long-term debt	1,043	432
Accounts payable and other current liabilities	2,569	2,676
Total current liabilities	3,612	3,108
Long-term debt, less current portion	9,323	9,594
Other liabilities	4,021	3,672
Total liabilities	16,956	16,374
Equity:
Stockholders' equity	6,415	6,275
Noncontrolling interests	2	1
Total equity	6,417	6,276	$ 6,065	$ 6,042
Total liabilities and equity	23,373	22,650
Eliminations [Member]
Current assets:
Other current assets	(137)
Total current assets	(137)
Investments in affiliates	(50,692)	(49,773)
Advances to affiliates	(17,391)	(17,258)
Total assets	(68,220)	(67,031)
Current liabilities:
Accounts payable and other current liabilities	(137)
Total current liabilities	(137)
Due to affiliates	(24,389)	(24,253)
Total liabilities	(24,526)	(24,253)
Equity:
Stockholders' equity	(50,692)	(49,773)
Advances to affiliates	6,998	6,995
Total equity	(43,694)	(42,778)
Total liabilities and equity	(68,220)	(67,031)
WM [Member] | Reportable Legal Entities [Member]
Current assets:
Other current assets	167	2
Total current assets	167	2
Investments in affiliates	25,116	24,676
Other assets	6	8
Total assets	25,289	24,686
Current liabilities:
Current portion of long-term debt	903	258
Accounts payable and other current liabilities	68	82
Total current liabilities	971	340
Long-term debt, less current portion	7,098	7,377
Due to affiliates	17,511	17,398
Other liabilities	3	5
Total liabilities	25,583	25,120
Equity:
Stockholders' equity	6,415	6,275
Advances to affiliates	(6,709)	(6,709)
Total equity	(294)	(434)
Total liabilities and equity	25,289	24,686
WM Holdings [Member] | Reportable Legal Entities [Member]
Current assets:
Other current assets	6	5
Total current assets	6	5
Investments in affiliates	25,576	25,097
Other assets	11	31
Total assets	25,593	25,133
Current liabilities:
Accounts payable and other current liabilities	6	9
Total current liabilities	6	9
Long-term debt, less current portion	304	304
Due to affiliates	169	146
Total liabilities	479	459
Equity:
Stockholders' equity	25,114	24,674
Total equity	25,114	24,674
Total liabilities and equity	25,593	25,133
Non-Guarantor Subsidiaries [Member] | Reportable Legal Entities [Member]
Current assets:
Cash and cash equivalents	57	61
Other current assets	2,395	2,577
Total current assets	2,452	2,638
Property and equipment, net	12,390	11,942
Advances to affiliates	17,391	17,258
Other assets	8,478	8,024
Total assets	40,711	39,862
Current liabilities:
Current portion of long-term debt	140	174
Accounts payable and other current liabilities	2,632	2,585
Total current liabilities	2,772	2,759
Long-term debt, less current portion	1,921	1,913
Due to affiliates	6,709	6,709
Other liabilities	4,018	3,667
Total liabilities	15,420	15,048
Equity:
Stockholders' equity	25,578	25,099
Advances to affiliates	(289)	(286)
Noncontrolling interests	2	1
Total equity	25,291	24,814
Total liabilities and equity	$ 40,711	$ 39,862