Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net income	$ 9,148	$ 10,043
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, accretion, and amortization expense	22,033	19,225
Amortization of deferred financing costs	229	220
Stock-based compensation expense	3,165	2,560
Deferred income taxes	1,433	5,380
Loss on disposal of assets	203	548
Unrealized gain on derivative instruments		(129)
Amortization of accumulated other comprehensive gains associated with derivative instruments no longer designated as hedging instruments		(45)
Other reserves and non-cash items	1,157	454
Changes in assets and liabilities:
Increase in accounts and notes receivable, net	(4,457)	(7,332)
Decrease in prepaid, deferred costs, and other current assets	14,526	564
Increase in inventory	(219)	(2,593)
Increase (decrease) in other assets	(1,507)	2,931
Decrease in accounts payable	(2,722)	(6,857)
Increase (decrease) in accrued liabilities	113	(4,731)
Decrease in other liabilities	(1,722)	(1,497)
Net cash provided by operating activities	41,380	18,741
Cash flows from investing activities:
Additions to property and equipment	(15,145)	(21,324)
Payments for exclusive license agreements, site acquisition costs and other intangible assets	(792)	(362)
Acquisitions, net of cash acquired	(12,587)	(250)
Net cash used in investing activities	(28,524)	(21,936)
Cash flows from financing activities:
Proceeds from borrowings of long-term debt	57,200	53,700
Repayments of long-term debt and capital leases	(58,169)	(49,470)
Repayments of borrowings under bank overdraft facility, net		(212)
Payment of contingent consideration	(250)
Proceeds from exercises of stock options	247	1,264
Excess tax benefit from stock-based compensation expense	3,966
Repurchase of capital stock	(3,804)	(1,406)
Net cash (used in) provided by financing activities	(810)	3,876
Effect of exchange rate changes on cash	219	(44)
Net increase in cash and cash equivalents	12,265	637
Cash and cash equivalents as of beginning of period	13,861	5,576
Cash and cash equivalents as of end of period	26,126	6,213
Supplemental disclosure of cash flow information:
Cash paid for interest, including interest on capital leases	9,115	9,545
Cash paid for income taxes	$ 534	$ 744