Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net income	$ 87,910	$ 65,981	$ 35,194
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, accretion, and amortization of intangible assets	127,775	123,829	111,390
Amortization of deferred financing costs and note discount	11,529	11,363	13,036
Share-based compensation expense	21,430	19,454	16,502
Deferred income taxes	9,886	10,993	3,038
Loss (gain) on disposal of assets	81	(14,010)	3,224
Other reserves and non-cash items	1,901	3,145	5,188
Redemption costs for early extinguishment of debt			9,075
Changes in assets and liabilities:
(Increase) decrease in accounts and notes receivable, net	(16,284)	17,384	(12,224)
Increase in prepaid expenses, deferred costs, and other current assets	(12,491)	(19,588)	(7,578)
Increase in inventory, net	(1,191)	(4,668)	(2,399)
(Increase) decrease in other assets	(21,955)	8,415	(4,175)
Increase (decrease) in accounts payable	15,468	(8,016)	(4,940)
Increase in accrued liabilities	46,508	31,889	20,100
(Decrease) increase in other liabilities	(292)	10,382	3,122
Net cash provided by operating activities	270,275	256,553	188,553
Cash flows from investing activities:
Additions to property and equipment	(125,882)	(142,349)	(109,909)
Acquisitions, net of cash acquired	(22,669)	(103,874)	(226,972)
Proceeds from sale of assets and businesses	9,348	36,661
Net cash used in investing activities	(139,203)	(209,562)	(336,881)
Cash flows from financing activities:
Proceeds from borrowings under revolving credit facility	235,368	452,670	127,657
Repayments of borrowings under revolving credit facility	(311,362)	(499,551)	(61,539)
Proceeds from borrowings of long-term debt			250,000
Repayment of long-term debt			(200,000)
Debt issuance, modification and redemption costs			(14,746)
Payment of contingent acquisition consideration			(517)
Proceeds from exercises of stock options	673	1,107	810
Additional tax benefit related to share-based compensation	338	1,985	4,739
Repurchase of common shares	(3,959)	(4,731)	(7,156)
Net cash (used in) provided by financing activities	(78,942)	(48,520)	99,248
Effect of exchange rate changes on cash	(4,893)	(4,049)	(5,984)
Net increase (decrease) in cash and cash equivalents	47,237	(5,578)	(55,064)
Cash and cash equivalents as of beginning of period	26,297	31,875	86,939
Cash and cash equivalents as of end of period	73,534	26,297	31,875
Supplemental disclosure of cash flow information:
Cash paid for interest	16,718	19,494	21,094
Cash paid for income taxes	$ 17,886	$ 28,292	$ 26,014