Segment and Related Information - Summary (Detail) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) segment	Jun. 30, 2024 USD ($)
Segment Reporting
Number of reportable segments | segment			5
Net operating revenue royalty (as a percent)	15.00%		15.00%
Royalty amount	$ 17	$ 11	$ 31	$ 21
Operating revenues	6,430	5,402	12,448	10,561
Operating expenses	3,839	3,291	7,486	6,431
Selling, general and administrative	696	501	1,383	992
Other net expenses	36	58	51	56
Depreciation, depletion and amortization	708	543	1,364	1,057
Income from operations	1,151	1,009	2,164	2,025
Capital expenditures	815	776	1,456	1,329
Collection and Disposal [Member]
Segment Reporting
Operating revenues	5,281	4,922	10,203	9,638
Other net expenses	26	2	26
Depreciation, depletion and amortization	517	475	994	925
Income from operations	1,461	1,359	2,806	2,638
Capital expenditures	707	474	1,143	863
Collection and Disposal [Member] | East Tier [Member]
Segment Reporting
Operating revenues	2,292	2,178	4,432	4,259
Other net expenses	8	2	8	2
Depreciation, depletion and amortization	272	253	523	494
Income from operations	721	692	1,390	1,346
Capital expenditures	360	245	557	421
Collection and Disposal [Member] | West Tier [Member]
Segment Reporting
Operating revenues	2,251	2,076	4,333	4,069
Other net expenses	2		2
Depreciation, depletion and amortization	239	214	458	418
Income from operations	757	674	1,436	1,301
Capital expenditures	335	218	557	419
Collection and Disposal [Member] | Other Ancillary [Member]
Segment Reporting
Operating revenues	738	668	1,438	1,310
Other net expenses	16		16	(2)
Depreciation, depletion and amortization	6	8	13	13
Income from operations	(17)	(7)	(20)	(9)
Capital expenditures	12	11	29	23
Recycling Processing and Sales [Member]
Segment Reporting
Operating revenues	381	405	765	773
Other net expenses	1		6
Depreciation, depletion and amortization	45	31	84	60
Income from operations	24	29	42	48
Capital expenditures	70	140	108	227
WM Renewable Energy [Member]
Segment Reporting
Operating revenues	115	69	206	138
Depreciation, depletion and amortization	15	9	30	17
Income from operations	38	18	57	39
Capital expenditures	115	123	237	214
WM Healthcare Solutions [Member]
Segment Reporting
Operating revenues	646		1,265
Other net expenses	9		18
Depreciation, depletion and amortization	105		206
Income from operations	(23)		(44)
Capital expenditures	46		80
Corporate and Other [Member]
Segment Reporting
Operating revenues	7	6	9	12
Other net expenses		56	1	56
Depreciation, depletion and amortization	26	28	50	55
Income from operations	(349)	(397)	(697)	(700)
Capital expenditures	(123)	39	(112)	25
Operating Segments [Member]
Segment Reporting
Operating revenues	7,775	6,610	15,007	12,901
Operating expenses	5,177	4,494	10,033	8,761
Selling, general and administrative	703	506	1,395	1,002
Operating Segments [Member] | Collection and Disposal [Member]
Segment Reporting
Operating revenues	6,516	6,051	12,554	11,825
Operating expenses	4,307	4,005	8,322	7,843
Selling, general and administrative	205	210	406	419
Operating Segments [Member] | Collection and Disposal [Member] | Processing fees [Member]
Segment Reporting
Income from operations	(20)	(26)	(40)	(48)
Operating Segments [Member] | Collection and Disposal [Member] | East Tier [Member]
Segment Reporting
Operating revenues	2,922	2,744	5,620	5,352
Operating expenses	1,833	1,708	3,523	3,332
Selling, general and administrative	88	89	176	178
Operating Segments [Member] | Collection and Disposal [Member] | West Tier [Member]
Segment Reporting
Operating revenues	2,805	2,594	5,393	5,074
Operating expenses	1,721	1,614	3,328	3,172
Selling, general and administrative	86	92	169	183
Operating Segments [Member] | Collection and Disposal [Member] | Other Ancillary [Member]
Segment Reporting
Operating revenues	789	713	1,541	1,399
Operating expenses	753	683	1,471	1,339
Selling, general and administrative	31	29	61	58
Operating Segments [Member] | Recycling Processing and Sales [Member]
Segment Reporting
Operating revenues	482	475	947	911
Operating expenses	398	399	786	773
Selling, general and administrative	14	16	29	30
Operating Segments [Member] | WM Renewable Energy [Member]
Segment Reporting
Operating revenues	115	70	207	140
Operating expenses	59	40	114	79
Selling, general and administrative	3	3	6	5
Operating Segments [Member] | WM Healthcare Solutions [Member]
Segment Reporting
Operating revenues	647		1,274
Operating expenses	406		789
Selling, general and administrative	150		305
Operating Segments [Member] | Corporate and Other [Member]
Segment Reporting
Operating revenues	15	14	25	25
Operating expenses	7	50	22	66
Selling, general and administrative	331	277	649	548
Intercompany Elimination [Member]
Segment Reporting
Operating revenues	1,345	1,208	2,559	2,340
Operating expenses	1,338	1,203	2,547	2,330
Selling, general and administrative	(7)	(5)	(12)	(10)
Intercompany Elimination [Member] | Collection and Disposal [Member]
Segment Reporting
Operating revenues	1,235	1,129	2,351	2,187
Intercompany Elimination [Member] | Collection and Disposal [Member] | East Tier [Member]
Segment Reporting
Operating revenues	630	566	1,188	1,093
Intercompany Elimination [Member] | Collection and Disposal [Member] | West Tier [Member]
Segment Reporting
Operating revenues	554	518	1,060	1,005
Intercompany Elimination [Member] | Collection and Disposal [Member] | Other Ancillary [Member]
Segment Reporting
Operating revenues	51	45	103	89
Intercompany Elimination [Member] | Recycling Processing and Sales [Member]
Segment Reporting
Operating revenues	101	70	182	138
Intercompany Elimination [Member] | WM Renewable Energy [Member]
Segment Reporting
Operating revenues		1	1	2
Intercompany Elimination [Member] | WM Healthcare Solutions [Member]
Segment Reporting
Operating revenues	1		9
Intercompany Elimination [Member] | Corporate and Other [Member]
Segment Reporting
Operating revenues	$ 8	$ 8	$ 16	$ 13