Supplemental Guarantor Financial Information - Cash Flows (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	$ 213,931	$ 147,112
Additions to property and equipment	(76,050)	(103,877)
Acquisitions, net of cash acquired	(19,701)	(103,874)
Proceeds from sale of assets and businesses	9,348	36,661
Net cash used in investing activities	(86,403)	(171,090)
Proceeds from borrowings under revolving credit facility	221,268	340,250
Repayments of borrowings under revolving credit facility	(311,361)	(324,216)
Proceeds from exercises of stock options	579	586
Additional tax benefit (expense) related to stock-based compensation	338	1,287
Repurchase of capital stock	(3,959)	(4,610)
Net cash (used in) provided by financing activities	(93,135)	13,297
Effect of exchange rate changes on cash	(1,169)	(2,711)
Net increase (decrease) in cash and cash equivalents	33,224	(13,392)
Cash and cash equivalents as of beginning of period	26,297	31,875
Cash and cash equivalents as of end of period	59,521	18,483
Parent
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	(1,114)
Proceeds from exercises of stock options	433
Additional tax benefit (expense) related to stock-based compensation	681
Net cash (used in) provided by financing activities	1,114
Issuer
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	75,563	(61,118)
Proceeds from borrowings under revolving credit facility	221,268	312,500
Repayments of borrowings under revolving credit facility	(311,361)	(324,186)
Repayments of intercompany notes payable	17,911	75,545
Proceeds from exercises of stock options	146	586
Additional tax benefit (expense) related to stock-based compensation	(343)	1,287
Repurchase of capital stock	(3,959)	(4,610)
Net cash (used in) provided by financing activities	(76,338)	61,122
Net increase (decrease) in cash and cash equivalents	(775)	4
Cash and cash equivalents as of beginning of period	782
Cash and cash equivalents as of end of period	7	4
Guarantors
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	70,451	138,448
Additions to property and equipment	(33,603)	(64,411)
Acquisitions, net of cash acquired	(14,544)	(80,504)
Net cash used in investing activities	(48,147)	(144,915)
Repayments of intercompany notes payable		(750)
Net cash (used in) provided by financing activities		(750)
Net increase (decrease) in cash and cash equivalents	22,304	(7,217)
Cash and cash equivalents as of beginning of period	6,200	9,391
Cash and cash equivalents as of end of period	28,504	2,174
Non-Guarantors
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	69,031	69,782
Additions to property and equipment	(42,447)	(39,466)
Acquisitions, net of cash acquired	(5,157)	(23,370)
Proceeds from sale of assets and businesses	9,348	36,661
Net cash used in investing activities	(38,256)	(26,175)
Proceeds from borrowings under revolving credit facility		27,750
Repayments of borrowings under revolving credit facility		(30)
Repayments of intercompany notes payable	(17,911)	(74,795)
Net cash (used in) provided by financing activities	(17,911)	(47,075)
Effect of exchange rate changes on cash	(1,169)	(2,711)
Net increase (decrease) in cash and cash equivalents	11,695	(6,179)
Cash and cash equivalents as of beginning of period	19,315	22,484
Cash and cash equivalents as of end of period	$ 31,010	$ 16,305