Acquisitions (Summary of Consideration Transferred to Acquire Businesses and Amounts of Identifiable Assets Acquired, Liabilities Assumed and Noncontrolling Interests) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended				1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012		Oct. 31, 2012	Oct. 25, 2012
Fair value of consideration transferred:
Cash	$ 126,181	$ 64,156	$ 241,525
Debt assumed			12,986	[1]
Contingent consideration	42,538	40	21,314
Total fair value of consideration transferred	168,719	64,196	275,825
Recognized amounts of identifiable assets acquired and liabilities assumed associated with businesses acquired:
Accounts receivable	3,785	211	10,874
Other current assets	111	317	1,062
Restricted assets			6,725
Property and equipment	140,412	12,775	127,023
Long-term franchise agreements and contracts	369	1,043	10,307
Indefinite-lived intangibles			35,344
Customer lists	9,420	13,024	21,837
Permits			2,295
Other long-term assets			185
Deferred revenue	(427)	(539)	(5,056)
Accounts payable		(735)	(3,393)
Accrued liabilities	(1,749)	(1,034)	(2,139)
Other long-term liabilities	(1,980)	(767)	(3,480)
Total identifiable net assets	149,941	24,295	201,584
Goodwill	18,778	39,901	74,241
R360 Environmental Solutions Inc [Member]
Fair value of consideration transferred:
Cash			1,338,344
Debt assumed			9,306	[2]	9,306
Contingent consideration			37,293			37,293
Total fair value of consideration transferred			1,384,943
Recognized amounts of identifiable assets acquired and liabilities assumed associated with businesses acquired:
Accounts receivable			50,161
Other current assets			19,716
Property and equipment			894,651
Indefinite-lived intangibles			27,096
Customer lists			21,016
Accounts payable			(31,702)
Accrued liabilities			(19,286)
Other long-term liabilities			(8,066)
Deferred income taxes			(14,568)
Total identifiable net assets			939,018
Goodwill			$ 445,925

[1] Debt assumed as part of 2012 acquisitions was paid at close of acquisition.

[2] Debt assumed was paid at close of acquisition.