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 (loss)	$ (1,292)	$ 14,172
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation and amortization	46,285	38,373
Allowance for doubtful accounts	281	(94)
(Gain) loss on dispositions of property and equipment	(321)	(733)
Stock-based compensation expense	1,512	2,000
Amortization of debt issuance costs, discount and premium	762	732
Impairment of equipment	0	1,032
Deferred income taxes	(1,287)	5,846
Change in other long-term assets	(2,658)	720
Change in other long-term liabilities	953	219
Changes in current assets and liabilities:
Receivables	(4,252)	(17,320)
Inventory	(226)	(1,036)
Prepaid expenses and other current assets	3,640	(644)
Accounts payable	(6,713)	1,407
Deferred revenues	(1,663)	767
Accrued expenses	(17,864)	(15,789)
Net cash provided by operating activities	17,157	29,652
Cash flows from investing activities:
Purchases of property and equipment	(71,313)	(95,109)
Proceeds from sale of property and equipment	1,567	1,357
Net cash used in investing activities	(69,746)	(93,752)
Cash flows from financing activities:
Debt repayments	(656)	(656)
Proceeds from issuance of debt	40,000	0
Proceeds from exercise of options	295	253
Purchase of treasury stock	(275)	(293)
Net cash provided by financing activities	39,364	(696)
Net (decrease) increase in cash and cash equivalents	(13,225)	(64,796)
Beginning cash and cash equivalents	23,733	86,197
Ending cash and cash equivalents	10,508	21,401
Supplementary disclosure:
Interest paid	21,956	21,343
Income taxes paid (refunded)	$ 320	$ (1,074)