Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Cash Flows from Operating Activities:
Net income (loss)	$ 4,532	$ 20,653
Amounts to reconcile net income to net cash flows provided by operating activities:
Benefit for deferred income taxes	(241)	(1,070)
Depreciation and amortization	28,570	28,003
Amortization of deferred financing costs	1,396	1,421
Amortization of discount on convertible notes		3,274
Impairment and other charges	2,890
Loss on repurchase of warrants	20,186
Stock-based compensation expense	1,591	1,281
Changes in:
Trade receivables	(24,976)	(15,373)
Interest receivable	379	422
Accounts payable and accrued liabilities	(27,817)	(13,299)
Other assets and liabilities	(2,638)	4,519
Net cash flows provided by operating activities	3,872	29,831
Cash Flows from Investing Activities:
Purchases of property and equipment	(18,655)	(17,484)
Proceeds from sale of Peterson LOI	10,000
(Increase) decrease in restricted cash and cash equivalents	(3,594)	9,509
Other investing activities	(2,453)
Net cash flows used in investing activities	(14,702)	(7,975)
Cash Flows from Financing Activities:
Net borrowings (repayments) under credit facility	171,000	(3,500)
Repayments under term loan B	(1,000)
Repurchase of common stock warrants	(154,681)
Payment of dividend	(28,756)	(25,459)
Proceeds from exercise of stock option and purchase plans	1,015	1,078
Other financing activities	(157)	(137)
Net cash flows used in financing activities	(12,579)	(28,018)
Net change in cash and cash equivalents	(23,409)	(6,162)
Cash and cash equivalents - unrestricted, beginning of period	76,408	61,579
Cash and cash equivalents - unrestricted, end of period	$ 52,999	$ 55,417