Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data	Jun. 30, 2011	Dec. 31, 2010
Current assets:
Allowance for doubtful accounts	$ 24	$ 26
Long-term assets
Accumulated depreciation and amortization	$ 14,957	$ 14,690
Waste Management, Inc. stockholders' equity:
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,500,000,000	1,500,000,000
Common stock, shares issued	630,282,461	630,282,461
Treasury stock, shares	157,950,900	155,235,711