Condensed Consolidating Financial Statements (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 237	$ 258	$ 371	$ 539
Other current assets	2,217	2,121
Total current assets	2,454	2,379
Property and equipment, net	12,360	12,242
Other assets	7,877	7,948
Total assets	22,691	22,569
Current liabilities:
Current portion of long-term debt	853	631
Accounts payable and other current liabilities	2,334	2,437
Total current liabilities	3,187	3,068
Long-term debt, less current portion	8,973	9,125
Other liabilities	4,044	3,986
Total liabilities	16,204	16,179
Equity:
Stockholders' equity	6,168	6,070
Noncontrolling interests	319	320
Total equity	6,487	6,390
Total liabilities and equity	22,691	22,569
WM [Member]
Current assets:
Cash and cash equivalents	112	119	325	465
Other current assets		6
Total current assets	112	125
Investments in and advances to affiliates	12,338	12,006
Other assets	44	120
Total assets	12,494	12,251
Current liabilities:
Current portion of long-term debt	552	298
Accounts payable and other current liabilities	150	124
Total current liabilities	702	422
Long-term debt, less current portion	5,580	5,727
Other liabilities	44	32
Total liabilities	6,326	6,181
Equity:
Stockholders' equity	6,168	6,070
Total equity	6,168	6,070
Total liabilities and equity	12,494	12,251
WM Holdings [Member]
Current assets:
Investments in and advances to affiliates	16,156	14,905
Other assets	12	12
Total assets	16,168	14,917
Current liabilities:
Accounts payable and other current liabilities	13	13
Total current liabilities	13	13
Long-term debt, less current portion	449	449
Total liabilities	462	462
Equity:
Stockholders' equity	15,706	14,455
Total equity	15,706	14,455
Total liabilities and equity	16,168	14,917
Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	125	139	46	74
Other current assets	2,217	2,115
Total current assets	2,342	2,254
Property and equipment, net	12,360	12,242
Investments in and advances to affiliates	3,201	3,033
Other assets	7,821	7,816
Total assets	25,724	25,345
Current liabilities:
Current portion of long-term debt	301	333
Accounts payable and other current liabilities	2,171	2,300
Total current liabilities	2,472	2,633
Long-term debt, less current portion	2,944	2,949
Other liabilities	4,000	3,954
Total liabilities	9,416	9,536
Equity:
Stockholders' equity	15,989	15,489
Noncontrolling interests	319	320
Total equity	16,308	15,809
Total liabilities and equity	25,724	25,345
Eliminations [Member]
Current assets:
Investments in and advances to affiliates	(31,695)	(29,944)
Total assets	(31,695)	(29,944)
Equity:
Stockholders' equity	(31,695)	(29,944)
Total equity	(31,695)	(29,944)
Total liabilities and equity	$ (31,695)	$ (29,944)