CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash Flows from Operating Activities:
Net income	$ 15,400	$ 5,126
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	14,496	10,594
Stock-based compensation expense	3,647	9,159
Deferred income taxes	(155)
(Gain) loss on sale of property and equipment	285	(276)
Other long-term liabilities	(4,061)	2,381
Other non-cash items	1,399	(2,227)
Changes in other components of working capital	(15,067)	(27,081)
NET CASH PROVIDED BY (USED IN) OPERATING ACTIVITIES	15,944	(2,324)
Cash Flows from Investing Activities:
Acquisition of property and equipment excluding financed purchases	(4,812)	(5,691)
Proceeds from sale of property and equipment	939	798
Change in restricted cash	(3,305)	277
NET CASH USED IN INVESTING ACTIVITIES	(7,178)	(4,616)
Cash Flows from Financing Activities:
Proceeds from debt	299,785	280,200
Repayment of debt	(287,484)	(262,112)
Issuance of common stock and effect of cashless exercise		(773)
Debt issuance costs	(5,937)
NET CASH PROVIDED BY FINANCING ACTIVITIES	6,364	17,315
Net increase in cash and cash equivalents	15,130	10,375
Cash and cash equivalents at beginning of year	75,452	135,583
Cash and cash equivalents at end of period	$ 90,582	$ 145,958