Acquisitions (Narrative) (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended				1 Months Ended		2 Months Ended	1 Months Ended			12 Months Ended	0 Months Ended	1 Months Ended			3 Months Ended
	Dec. 31, 2014 entity	Dec. 31, 2013	Dec. 31, 2012 entity		Dec. 31, 2012	Oct. 31, 2012	Dec. 31, 2012	Nov. 30, 2012	Jul. 31, 2013	Jul. 31, 2012	Jun. 30, 2013	Mar. 01, 2012	Mar. 31, 2012	Sep. 30, 2014	Oct. 31, 2014	Dec. 31, 2014	Mar. 31, 2013	Oct. 25, 2012 property
Business Acquisition [Line Items]
Cash consideration, net of cash acquired	$ 126,181	$ 64,156	$ 1,579,869
Debt assumed			12,986	[1]
Goodwill expected to be deductible for tax purposes	18,778	39,731														18,778
Trade receivables acquired in business combination gross contractual amount	3,981	414														3,981
Trade receivables acquired In business combination expected to be uncollectible amount	196	203														196
Acquisition related costs	2,147	1,946
Amount paid for purchased operations	126,181	64,156	241,525
Number of individual businesses acquired that are not specifically described	5		10
Goodwill	18,778	39,901	74,241		74,241		74,241									18,778
Fair value of acquired working capital is provisional	3
Dunn & Company LLC [Member]
Business Acquisition [Line Items]
Contingent consideration payable period	2 years
Contingent consideration	2,923															2,923
Dunn & Company LLC [Member] | Maximum [Member]
Business Acquisition [Line Items]
Contingent consideration payment discount rate	2.70%
Contingent consideration	3,000															3,000
Dunn & Company LLC [Member] | Minimum [Member]
Business Acquisition [Line Items]
Contingent consideration payment discount rate	2.40%
Claco Services [Member]
Business Acquisition [Line Items]
Contingent consideration payable period end date	2013-12
Payment of contingent consideration gross		375			375
Claco Services [Member] | Maximum [Member]
Business Acquisition [Line Items]
Contingent consideration		750
Prairie Disposal [Member]
Business Acquisition [Line Items]
Contingent consideration payable period			2 years
Contingent consideration payment discount rate			2.00%
Payment of contingent consideration gross	25,000
Prairie Disposal [Member] | Maximum [Member]
Business Acquisition [Line Items]
Contingent consideration			25,000		25,000		25,000
Calpet [Member]
Business Acquisition [Line Items]
Contingent consideration payable period			1 year
Contingent consideration payable period end date	2013-06
Contingent consideration payment discount rate			2.00%
Contingent consideration earned and paid to former owners	471	2,500
Contingent consideration not earned and expensed		1,250
Calpet [Member] | Maximum [Member]
Business Acquisition [Line Items]
Contingent consideration		4,221
R360 Environmental Solutions Inc [Member]
Business Acquisition [Line Items]
Cash consideration, net of cash acquired			1,338,344
Debt assumed			9,306	[2]		9,306
Number of operating locations																		24
Revenue generated from acquired entity and included in consolidated revenues							40,190
Total pre-tax earnings from acquired entity and included in consolidated income before income taxes							8,669
Goodwill expected to be deductible for tax purposes			395,339		395,339		395,339
Payment for the estimated net working capital for acquisition						18,906
Adjustment to net working capital																	18,000
Trade receivables acquired in business combination gross contractual amount			52,777		52,777		52,777
Trade receivables acquired In business combination expected to be uncollectible amount			2,616		2,616		2,616
Acquisition related costs			2,655
Amount paid for purchased operations			1,338,344
Goodwill			445,925		445,925		445,925
Contingent consideration			37,293		37,293		37,293											37,293
R360 Environmental Solutions Inc [Member] | Claco Services [Member]
Business Acquisition [Line Items]
Contingent consideration			741		741		741
R360 Environmental Solutions Inc [Member] | Prairie Disposal [Member]
Business Acquisition [Line Items]
Contingent consideration			24,376		24,376		24,376
R360 Environmental Solutions Inc [Member] | Oilfield Holdings [Member]
Business Acquisition [Line Items]
Payment of contingent consideration gross								8,000
Contingent consideration			8,000		8,000		8,000	8,000
R360 Environmental Solutions Inc [Member] | Calpet [Member]
Business Acquisition [Line Items]
Contingent consideration			4,176		4,176		4,176
R360 Environmental Solutions Inc [Member] | Senior Revolving Credit Facility [Member]
Business Acquisition [Line Items]
Business acquisition cost financed through borrowing																		475,000
R360 Environmental Solutions Inc [Member] | Unsecured Term Loan Facility [Member]
Business Acquisition [Line Items]
Business acquisition cost financed through borrowing						800,000
Other Acquisition [Member]
Business Acquisition [Line Items]
Trade receivables acquired in business combination gross contractual amount			10,984		10,984		10,984
Trade receivables acquired In business combination expected to be uncollectible amount			110		110		110
Number of individual businesses acquired that are not specifically described		8
Other Acquisitions [Member]
Business Acquisition [Line Items]
Goodwill expected to be deductible for tax purposes			74,241		74,241		74,241
Payment of contingent consideration gross			4,099
Acquisition related costs			2,658
SKB Environmental Inc [Member]
Business Acquisition [Line Items]
Contingent consideration payment discount rate										2.00%
Payment of contingent consideration gross									25,768
Acquisition of interest										100.00%
Amount paid for purchased operations										86,763
Additional consideration, earn out period											1 year
Contingent consideration										20,711
Alaska Waste [Member]
Business Acquisition [Line Items]
Contingent consideration payment discount rate													2.80%
Acquisition of interest												100.00%
Amount paid for purchased operations												133,402
Additional consideration, earn out period			2 years
Contingent consideration												602
Alaska Waste [Member] | Maximum [Member]
Business Acquisition [Line Items]
Maximum additional consideration to former owners	4,000															4,000
Screwbean Landfill, LLC [Member] | Dunn & Company LLC [Member]
Business Acquisition [Line Items]
Cash consideration, net of cash acquired	27,020
Rumsey Environmental LLC [Member]
Business Acquisition [Line Items]
Cash consideration, net of cash acquired														16,000
Contingent consideration payable period	2 years
Contingent consideration payment discount rate	2.80%
Contingent consideration	1,891															1,891
Rumsey Environmental LLC [Member] | Maximum [Member]
Business Acquisition [Line Items]
Contingent consideration	2,000															2,000
Section 18 [Member]
Business Acquisition [Line Items]
Cash consideration, net of cash acquired															64,425
Contingent consideration payment discount rate																5.20%
Contingent consideration															37,724
Section 18 [Member] | Maximum [Member]
Business Acquisition [Line Items]
Contingent consideration payable period																4 years
Contingent consideration															$ 43,166
Section 18 [Member] | Minimum [Member]
Business Acquisition [Line Items]
Contingent consideration payable period																1 year

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

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