Acquisitions and Divestitures - Allocation of Purchase Price (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Mar. 26, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Property and equipment	$ 243		$ 6	$ 195
Goodwill	325		17	327
Other intangible assets	145		$ 9	$ 232
Deffenbaugh Disposal, Inc. [Member]
Business Acquisition [Line Items]
Cash and cash equivalents	15	$ 15
Accounts and other receivables	22	18
Parts and supplies	2	2
Deferred income tax asset	11	9
Other current assets	10	12
Property and equipment	207	212
Goodwill	159	140
Other intangible assets	100	134
Other assets	1	1
Accounts payable	(2)	(4)
Accrued liabilities	(20)	(12)
Deferred revenues	(6)	(5)
Landfill and environmental remediation liabilities	(18)	(21)
Deferred income tax liability	(52)	(65)
Other liabilities	(14)	(20)
Total purchase price	415	$ 416
Deffenbaugh Disposal, Inc. [Member] | Adjustments [Member]
Business Acquisition [Line Items]
Accounts and other receivables	4
Deferred income tax asset	2
Other current assets	(2)
Property and equipment	(5)
Goodwill	19
Other intangible assets	(34)
Accounts payable	2
Accrued liabilities	(8)
Deferred revenues	(1)
Landfill and environmental remediation liabilities	3
Deferred income tax liability	13
Other liabilities	6
Total purchase price	$ (1)