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	$ (31,266)	$ (39,792)	$ (26,279)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation and amortization	39,235	44,283	47,072
Noncash compensation	976	879	1,156
Deferred income tax expense (benefit)	763	(6,053)	(14,046)
Gain on proceeds from insurance settlements		(2,269)	(407)
Change in other accrued long-term liabilities	(1,489)	(195)	1,834
(Gain) loss on disposal of assets	(1,714)	(167)	815
Other	(91)	186	(81)
Change in current assets and liabilities:
(Increase) decrease in accounts receivable	(16,696)	19,669	15,883
Decrease in prepaid expenses and other current assets	401	1,328	1,752
Increase (decrease) in accounts payable	1,176	(4,326)	(3,128)
Increase (decrease) in accrued liabilities	1,458	(1,810)	(4,579)
Increase (decrease) in deferred revenue	544	(2,991)	620
Net cash (used in) provided by operating activities	(6,703)	8,742	20,612
CASH FLOWS FROM INVESTING ACTIVITIES:
Cash acquired from merger			12,382
Capital expenditures, net of noncash capital expenditures summarized below	(8,675)	(8,251)	(6,846)
Proceeds from maturity of short-term investments	61,250	91,750	34,500
Acquisition of short-term investments	(37,583)	(111,000)	(26,750)
Proceeds from disposal of assets	1,325	1,922	1,501
Proceeds from flood insurance claims	375	2,850	1,000
Proceeds from notes receivable	96
Net cash provided by (used in) investing activities	16,788	(22,729)	15,787
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from promissory note			5,144
Principal payments on notes payable	(2,186)	(7,554)	(16,348)
Principal payments on capital lease obligations	(1,076)	(780)	(1,535)
Excess tax benefit from share-based payment arrangement		(77)	(551)
Tax withholdings related to stock-based compensation awards	(158)	(72)	(316)
Net cash used in financing activities	(3,420)	(8,483)	(13,606)
Effect of exchange rate changes on cash and cash equivalents	724	85	(428)
Net increase (decrease) in cash and cash equivalents	7,389	(22,385)	22,365
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	14,624	37,009	14,644
CASH AND CASH EQUIVALENTS AT END OF PERIOD	22,013	14,624	37,009
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for interest	143	260	620
Cash paid for income taxes		33	692
Cash received for income taxes	4,791	348	752
NONCASH INVESTING AND FINANCING ACTIVITIES:
(Decrease) increase in accrued purchases of property and equipment	(907)	$ 1,542	(52)
Capital lease obligations incurred	8,542		126
Stock consideration to consummate the merger			42,902
Financed insurance premiums	248		$ 1,046
Equipment sales financed for buyer	(1,500)
Sales tax on equipment sales financed for buyer	$ (132)