Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash Flows from Operating Activities:
Net income (loss)	$ 45,921	$ 48,644
Amounts to reconcile net income to net cash flows provided by operating activities:
Provision (benefit) for deferred income taxes	244	(1,088)
Depreciation and amortization	56,969	56,235
Amortization of deferred financing costs	2,854	2,837
Amortization of discount on convertible notes		6,028
Impairment and other charges	2,890
Loss on extinguishment of debt		2,148
Loss on repurchase of warrants	20,246	4,496
Write-off of deferred financing costs	1,928
Stock-based compensation expense	3,057	2,728
Changes in:
Trade receivables	(23,324)	(4,135)
Interest receivable	(3,003)	(2,609)
Accounts payable and accrued liabilities	(32,750)	(23,579)
Other assets and liabilities	578	4
Net cash flows provided by operating activities	75,610	91,709
Cash Flows from Investing Activities:
Purchases of property and equipment	(38,818)	(35,773)
Proceeds from sale of Peterson LOI	10,000
(Increase) decrease in restricted cash and cash equivalents	(7,860)	6,268
Other investing activities	340	398
Net cash flows used in investing activities	(36,338)	(29,107)
Cash Flows from Financing Activities:
Net repayments under credit facility	(246,000)	(209,500)
Borrowings (repayments) under term loan B	(2,000)	400,000
Issuance of senior notes	400,000
Repurchase and conversion of convertible notes		(126,541)
Repurchase of common stock warrants	(154,681)	(50,775)
Deferred financing costs paid	(10,723)	(8,158)
Payment of dividend	(62,070)	(53,389)
Proceeds from exercise of stock option and purchase plans	1,430	2,309
Other financing activities	(317)	(284)
Net cash flows used in financing activities	(74,361)	(46,338)
Net change in cash and cash equivalents	(35,089)	16,264
Cash and cash equivalents - unrestricted, beginning of period	76,408	61,579
Cash and cash equivalents - unrestricted, end of period	$ 41,319	$ 77,843