Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash Flows from Operating Activities:
Net loss	$ (6,669)	$ (11,755)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	2,783	3,271
Stock-based compensation	2,408	1,450
Discount accretion and other debt-related costs	20	1,417
Provision for uncollectible accounts	(4)	(160)
Change in fair value of warrant liability	15	(360)
Changes in assets and liabilities:
Receivables	(740)	912
Prepaid expenses	(470)	(537)
Other current assets	32	187
Other long-term assets	688	(325)
Accounts payable	36	(303)
Accrued compensation and related costs	(1,519)	714
Unearned revenue	2,889	(450)
Other current liabilities	2,669	(6)
Other long-term liabilities	(268)	(192)
Total adjustments	8,539	5,618
Net cash provided by (used in) operating activities	1,870	(6,137)
Cash Flows from Investing Activities:
Capital expenditures	(307)	(2,152)
Investment in intangible assets	(91)	(105)
Net cash used in investing activities	(398)	(2,257)
Cash Flows from Financing Activities:
Proceeds from line of credit	4,500	13,500
Repayments of line of credit	(13,000)
Repayments of term loan and other borrowings	(420)	(23,006)
Cash paid to satisfy tax withholding upon vesting of employee stock awards	(270)	(973)
Principal payments on capital lease obligations	(1,131)	(1,269)
Proceeds from issuance of common stock, net of costs		14,736
Proceeds from employee stock purchase plan	106	120
Fees paid for issuance of debt	(150)	(206)
Debt prepayment costs		(692)
Net cash (used in) provided by financing activities	(10,365)	2,210
Effect of exchange rate changes on cash and cash equivalents		(26)
Decrease in total cash	(8,893)	(6,210)
Cash and cash equivalents	9,044	12,538
Restricted cash (included in Other long-term assets on the Consolidated Balance Sheets)	2,675	4,210
Total cash, beginning of period	11,719	16,748
Cash and cash equivalents	2,826	7,138
Restricted cash (included in Other long-term assets on the Consolidated Balance Sheets)	0	3,400
Total cash, end of period	2,826	10,538
Non-Cash Investing and Financing Activities:
Capital lease obligations incurred	98	2,014
Capital equipment purchased on credit	98	2,014
Supplemental Disclosures of Cash Flow Information:
Interest paid	$ 572	$ 1,806