CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Cash flows from operating activities:
Net cash provided by operating activities	$ 48,521	$ 49,511
Cash flows from investing activities:
Purchases of property and equipment	(35,432)	(41,039)
Proceeds from dispositions of assets	2	433
Net cash used in investing activities	(35,430)	(40,606)
Cash flows from financing activities:
Proceeds from issuance of senior secured notes, net	170,512
Purchases of common stock	(2,934)
Proceeds from exercises of stock options	371	129
Repayments of capital lease obligations	(13,469)	(17,119)
Net cash provided by (used in) financing activities	154,480	(16,990)
Effect of exchange rate changes on cash	197	(9)
Net increase (decrease) in cash and cash equivalents	167,768	(8,094)
Cash and cash equivalents, beginning of period	56,283	55,929
Cash and cash equivalents, end of period	224,051	47,835
Supplemental disclosure of cash flow information:
Capital lease obligations incurred	$ 36,102	$ 19,936