CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows from Operating Activities:
Net loss	$ (45,273)	$ (124,742)	$ (48,443)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	74,993	76,948	92,655
Loss on disposal of property and equipment, net	(353)	8	674
Impairments	503	83,377	232
Amortization of debt discount and issuance costs	2,519	2,534	2,017
Stock-based compensation expense, net of capitalized amount	3,040	4,997	8,781
Equity in earnings of equity-method investment	(1,207)	(170)	(200)
Provision for doubtful accounts	1,049	1,093	1,354
Non-cash change in capital lease obligations	520	223	(1,437)
Non-cash change in exit activities and restructuring liability	6,291	4,409	2,241
Non-cash change in deferred rent	(3,554)	(2,152)	(1,704)
Deferred taxes	355	325	(3,966)
Payment of debt lender fees	(2,583)	(1,716)	0
Loss on extinguishment and modification of debt	6,785	0	0
Other, net	304	179	261
Changes in operating assets and liabilities:
Accounts receivable	(207)	1,476	(2,211)
Prepaid expenses, deposits and other assets	2,051	2,297	1,099
Accounts payable	(1,167)	1,568	(4,814)
Accrued and other liabilities	3,359	81	(4,206)
Deferred revenues	(1,297)	(476)	758
Exit activities and restructuring liability	(6,178)	(3,584)	(2,873)
Asset retirement obligation	(825)	(174)	0
Other liabilities	40	(52)	(10)
Net cash flows provided by operating activities	39,165	46,449	40,208
Cash Flows from Investing Activities:
Proceeds from sale of building	0	542	0
Purchases of property and equipment	(35,714)	(44,364)	(55,695)
Additions to acquired and developed technology	(735)	(1,828)	(1,462)
Proceeds from disposal of property and equipment	402	0	0
Acquisition, net of cash received	3,838	0	0
Net cash flows used in investing activities	(32,209)	(45,650)	(57,157)
Cash Flows from Financing Activities:
Proceeds from credit agreements	316,900	4,500	21,000
Proceeds from stock issuance	40,195	0	0
Principal payments on credit agreements	(339,900)	(3,000)	(3,000)
Payment of debt issuance costs	(10,194)	0	0
Payments on capital lease obligations	(9,714)	(9,472)	(7,879)
Proceeds from exercise of stock options	421	673	6,046
Acquisition of common stock for income tax withholdings	(235)	(530)	(1,710)
Other, net	(345)	(289)	833
Net cash flows (used in) provided by financing activities	(2,872)	(8,118)	15,290
Effect of exchange rates on cash and cash equivalents	130	(64)	(653)
Net increase (decrease) in cash and cash equivalents	4,214	(7,383)	(2,312)
Cash and cash equivalents at beginning of period	10,389	17,772	20,084
Cash and cash equivalents at end of period	14,603	10,389	17,772
Supplemental disclosure of cash flow information:
Cash paid for interest	37,692	29,561	26,427
Non-cash acquisition of property and equipment under capital leases	189,679	6,042	6,377
Additions to property and equipment included in accounts payable	$ 1,932	$ 1,873	$ 5,170