Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net income (loss)	$ 4,815	$ (6,722)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Stock-based compensation expense	5,769	4,645
Depreciation and amortization	1,730	1,916
Other	662	279
Changes in operating assets and liabilities:
Accounts receivable	(7,422)	(14,957)
Inventories	(3,809)	(5,153)
Contract assets	(549)	1,743
Prepaid expenses and other assets	1,345	847
Accounts payable	5,171	4,669
Accrued expenses and other liabilities	4,967	2,854
Deferred revenue	1,538	394
Net cash provided by (used in) operating activities	14,217	(9,485)
Cash flows from investing activities:
Purchases of property and equipment	(7,893)	(1,274)
Proceeds from sale of assets		2,500
Proceeds from maturities of investment securities	20,500
Net cash provided by investing activities	12,607	1,226
Cash flows from financing activities:
Proceeds from issuance of long-term debt		15,000
Payment of debt issuance costs		(136)
Proceeds from issuance of common stock, net		7,781
Proceeds from exercise of stock options	1,512	674
Taxes paid related to net share settlement of equity awards	(1,366)	(1,077)
Net cash provided by financing activities	146	22,242
Effect of exchange rate changes on cash	1	(1)
Net increase in cash and cash equivalents	26,971	13,982
Cash and cash equivalents:
Beginning of period	23,201	27,892
End of period	50,172	41,874
Supplemental disclosure of cash flow information:
Cash paid for interest	2,679	2,073
Supplemental disclosure of non-cash investing activities:
Purchases of property and equipment recorded in accounts payable and accrued expenses	$ 1,577	$ 881