CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Cash flows from operating activities:
Net (loss) income	$ 41,388	$ 11,062	$ 7,601
Adjustments to reconcile net (loss) income to net cash provided by (used in) operating activities:
Depreciation and amortization	8,254	8,505	13,634
(Recovery) provision for doubtful accounts	694	1,298	208
(Gain) loss on disposal of fixed assets	2,579	0	2,878
Stock-based compensation expense	13,737	10,664	7,958
Non-cash provision for restructuring	956	5,046	0
Non-cash interest expense	515	3,651	6,143
Gain on forgiveness of PPP loan	(7,800)	0	0
Unrealized foreign currency transaction losses (gains)	(2,101)	1,570	971
Benefit from deferred taxes	1,591	827	(6,309)
Changes in operating assets and liabilities:
Accounts receivable	875	(6,124)	(6,227)
Inventories	6,646	2,598	3,790
Prepaid expenses and other current assets	(1,156)	6,176	(44)
Accounts payable	5,032	(18,141)	626
Accrued expenses, compensation and benefits and other liabilities	69	10,432	(6,892)
Income taxes payable	(796)	(281)	91
Deferred revenue and contract assets	(7,994)	2,272	(4,787)
Net cash provided by operating activities	62,489	39,555	19,641
Cash flows from investing activities:
Purchases of property and equipment	(6,819)	(5,692)	(7,185)
Net cash used in investing activities	(6,819)	(5,692)	(7,185)
Cash flows from financing activities:
Proceeds from revolving line of credit	0	22,000	0
Repayment on revolving line of credit	0	(22,000)	0
Proceeds from long-term debt	180,000	7,800	79,292
Repayment of debt	(210,456)	(2,250)	(1,438)
Payments for repurchase of common stock	(24,787)	0	0
Payments for repurchase of outstanding notes	0	(28,867)	(76,269)
Proceeds from the issuance of common stock under employee stock plans	808	547	309
Common stock repurchases for tax withholdings for net settlement of equity awards	(19,557)	(2,365)	(3,586)
Prepayment penalty on extinguishment of debt	(1,169)	0	0
Partial retirement of the convertible notes conversion feature and capped call option unwind	0	875	27
Payments for credit facility issuance costs	(2,574)	(289)	(5,979)
Net cash used in financing activities	(77,735)	(24,549)	(7,644)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(1,016)	1,748	(331)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	(23,081)	11,062	4,481
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	60,556	83,637	72,575
Supplemental information: [Abstract]
Cash and Cash Equivalents, at Carrying Value	56,818	79,899	69,085
Restricted cash	2,416	1,422	1,663
Restricted Cash, Noncurrent	1,322	2,316	1,827
Cash (refunded) paid for income taxes, net	1,034	(391)	783
Cash paid for interest	7,439	17,499	12,262
Non-cash transaction - property and equipment included in accounts payable or accruals	$ 649	$ 0	$ 23