Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income (loss)	$ 10,315	$ 9,881	$ (10,975)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Depreciation and amortization	2,927	2,805	3,971
Stock-based compensation	2,280	1,526	1,433
Deferred income taxes	163	145	(450)
Other non-cash items	(86)	59	(156)
Changes in assets and liabilities:
Accounts receivable	11,805	(7,332)	(10,702)
Advance billings	3,014	(1,307)	(1,626)
Inventories	(12,939)	(7,519)	(5,317)
Prepaid expenses and other current assets	3,179	(4,878)	(536)
Other assets	250	34	85
Accounts payable	(5,292)	(3,979)	14,687
Accrued compensation and benefits and other current liabilities	(395)	4,149	(4,554)
Deferred revenue	(4,744)	(808)	1,830
Other liabilities	264	(434)	(526)
Net cash provided by (used in) operating activities	10,741	(7,658)	(12,836)
Cash flows from investing activities:
(Increase) decrease in restricted cash	167	69	(202)
Purchases of property and equipment	(1,357)	(1,395)	(1,171)
Proceeds from sales of property and equipment	0	12	0
Net cash used in investing activities	(1,190)	(1,314)	(1,373)
Cash flows from financing activities:
Proceeds from revolving credit facility, net of borrowing costs	0	0	28,611
Repayment of revolving credit facility	0	(14,000)	(15,000)
Proceeds from issuance of common stock, net	1,701	32,213	576
Net cash provided by financing activities	1,701	18,213	14,187
Effect of exchange rate changes on cash and cash equivalents	(585)	(1,059)	246
Net increase in cash and cash equivalents	10,667	8,182	224
Cash and cash equivalents, beginning of period	22,760	14,578	14,354
Cash and cash equivalents, end of period	33,427	22,760	14,578
Supplemental Disclosure:
Cash paid for interest	94	210	578
Cash paid for income taxes, net of refunds	$ 419	$ 107	$ 422