Segment and Related Information - Revenue mix (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Segment revenue
Operating revenues	$ 6,018	$ 5,159
Collection and Disposal [Member]
Segment revenue
Operating revenues	4,922	4,716
Collection [Member]
Segment revenue
Operating revenues	3,746	3,615
Commercial [Member]
Segment revenue
Operating revenues	1,380	1,316
Industrial [Member]
Segment revenue
Operating revenues	741	747
Residential [Member]
Segment revenue
Operating revenues	872	854
Other Collection [Member]
Segment revenue
Operating revenues	753	698
Landfill [Member]
Segment revenue
Operating revenues	840	792
Transfer [Member]
Segment revenue
Operating revenues	336	309
Recycling Processing and Sales [Member]
Segment revenue
Operating revenues	384	368
WM Renewable Energy [Member]
Segment revenue
Operating revenues	91	69
WM Healthcare Solutions [Member]
Segment revenue
Operating revenues	619
Corporate and other [Member]
Segment revenue
Operating revenues	2	6
Operating Segments [Member]
Segment revenue
Operating revenues	7,232	6,291
Operating Segments [Member] | Collection and Disposal [Member]
Segment revenue
Operating revenues	6,038	5,774
Operating Segments [Member] | Collection [Member]
Segment revenue
Operating revenues	4,253	4,062
Operating Segments [Member] | Commercial [Member]
Segment revenue
Operating revenues	1,594	1,501
Operating Segments [Member] | Industrial [Member]
Segment revenue
Operating revenues	940	934
Operating Segments [Member] | Residential [Member]
Segment revenue
Operating revenues	894	876
Operating Segments [Member] | Other Collection [Member]
Segment revenue
Operating revenues	825	751
Operating Segments [Member] | Landfill [Member]
Segment revenue
Operating revenues	1,193	1,152
Operating Segments [Member] | Transfer [Member]
Segment revenue
Operating revenues	592	560
Operating Segments [Member] | Recycling Processing and Sales [Member]
Segment revenue
Operating revenues	465	436
Operating Segments [Member] | WM Renewable Energy [Member]
Segment revenue
Operating revenues	92	70
Operating Segments [Member] | WM Healthcare Solutions [Member]
Segment revenue
Operating revenues	627
Operating Segments [Member] | Corporate and other [Member]
Segment revenue
Operating revenues	10	11
Intercompany Elimination [Member]
Segment revenue
Operating revenues	1,214	1,132
Intercompany Elimination [Member] | Collection and Disposal [Member]
Segment revenue
Operating revenues	1,116	1,058
Intercompany Elimination [Member] | Collection [Member]
Segment revenue
Operating revenues	507	447
Intercompany Elimination [Member] | Commercial [Member]
Segment revenue
Operating revenues	214	185
Intercompany Elimination [Member] | Industrial [Member]
Segment revenue
Operating revenues	199	187
Intercompany Elimination [Member] | Residential [Member]
Segment revenue
Operating revenues	22	22
Intercompany Elimination [Member] | Other Collection [Member]
Segment revenue
Operating revenues	72	53
Intercompany Elimination [Member] | Landfill [Member]
Segment revenue
Operating revenues	353	360
Intercompany Elimination [Member] | Transfer [Member]
Segment revenue
Operating revenues	256	251
Intercompany Elimination [Member] | Recycling Processing and Sales [Member]
Segment revenue
Operating revenues	81	68
Intercompany Elimination [Member] | WM Renewable Energy [Member]
Segment revenue
Operating revenues	1	1
Intercompany Elimination [Member] | WM Healthcare Solutions [Member]
Segment revenue
Operating revenues	8
Intercompany Elimination [Member] | Corporate and other [Member]
Segment revenue
Operating revenues	$ 8	$ 5