Acquisitions and Divestitures - Carrying Amount of Asset and Liabilities (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 19, 2014
Assets And Liabilities Carrying Value And Fair Value [Line Items]
Parts and supplies	$ 106	$ 178
Deferred income taxes	115	113
Other assets	176	163
Total current assets	3,641	2,499
Property and equipment	10,657	12,344	12,651
Goodwill	5,740	6,070	6,291
Other assets	526	747
Total assets	21,412	22,603	23,097
Accounts payable	740	744
Accrued liabilities	1,180	1,069
Deferred revenues	475	475
Total current liabilities	3,485	3,014
Deferred income taxes	1,453	1,842
Landfill and environmental remediation liabilities	1,531	1,518
Other liabilities	709	727
Total liabilities	15,523	16,601
Noncontrolling interests	23	295
Wheelabrator [Member]
Assets And Liabilities Carrying Value And Fair Value [Line Items]
Accounts and other receivables				90
Parts and supplies				65
Deferred income taxes				1
Other assets				12
Total current assets				168
Property and equipment				1,155
Goodwill		305	788	305
Other intangible assets				3
Other assets				215
Total assets		2,037	2,605	1,846
Accounts payable				23
Accrued liabilities				20
Deferred revenues				1
Current portion of long-term debt				1
Total current liabilities				45
Long-term debt, less current portion				14
Deferred income taxes				344
Landfill and environmental remediation liabilities				18
Other liabilities				19
Total liabilities				440
Noncontrolling interests				$ 31