Document and Entity Information - USD ($)
$ in Billions
12 Months Ended
Dec. 31, 2019
Feb. 07, 2020
Jun. 30, 2019
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Transition Report false    
Document Period End Date Dec. 31, 2019    
Entity File Number 1-12154    
Entity Registrant Name Waste Management, Inc    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 73-1309529    
Entity Address, Address Line One 1001 Fannin Street    
Entity Address, City or Town Houston    
Entity Address, State or Province TX    
Entity Address, Postal Zip Code 77002    
City Area Code 713    
Local Phone Number 512-6200    
Title of 12(b) Security Common Stock    
Trading Symbol WM    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Shell Company false    
Entity Common Stock, Shares Outstanding   424,708,758  
Entity Public Float     $ 48.8
Current Fiscal Year End Date --12-31    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Entity Central Index Key 0000823768    
Amendment Flag false