Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income (loss)	$ 2,062	$ (23,877)	$ (12,348)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Stock-based compensation	13,172	10,109	9,832
Depreciation and amortization	1,344	1,394	1,548
Amortization of contract acquisition costs	1,857	2,593	2,915
Amortization of debt issuance costs	710	0	0
Impairment of capitalized cloud computing costs	182	805	0
Change in deferred tax assets	(135)	(220)	34
Provision for credit losses	87	2,144	590
Gain on extinguishment of PPP loan	(7,185)	0	0
Change in right-of-use asset	2,292	2,522	2,502
Other	1	513	(83)
Changes in assets and liabilities:
Accounts receivable	(9,574)	(2,550)	(2,509)
Inventories	(10,936)	5,413	(5,907)
Other current assets and prepaid expenses	(5,766)	(3,164)	(1,762)
Other long-term assets	(7,128)	(2,067)	(3,355)
Accounts payable	1,207	(6,034)	1,406
Accrued liabilities	21,608	161	5,997
Other long-term liabilities	0	0	(140)
Operating lease liabilities	(2,151)	(1,598)	(2,292)
Deferred revenue	(412)	(2,985)	1,656
Income tax liability	0	(93)	(301)
Net cash provided by (used in) operating activities	1,235	(16,934)	(2,217)
Cash flows from investing activities:
Acquisition of property and equipment	(1,015)	(1,279)	(991)
Disposal of property and equipment	71	30	45
Proceeds from sales of marketable investments	0	5,648	0
Proceeds from maturities of marketable investments	0	28,050	14,700
Purchase of marketable investments	0	(26,060)	(12,687)
Net cash provided by (used in) investing activities	(944)	6,389	1,067
Cash flows from financing activities:
Proceeds from exercise of stock options and employee stock purchase plan	2,765	1,579	2,894
Purchase of capped call	(16,134)	0	0
Proceeds from PPP loan	0	7,167	0
Proceeds from issuance of convertible notes	138,250	0	0
Payment of issuance costs of convertible notes	(4,717)	0	0
Gross proceeds from equity offering	0	28,798	0
Issuance costs on the public offering	0	(2,303)	0
Taxes paid related to net share settlement of equity awards	(2,176)	(3,428)	(831)
Payments on capital lease obligation	(462)	(537)	(649)
Net cash provided by financing activities	117,526	31,276	1,414
Net increase in cash, cash equivalents, and restricted cash	117,817	20,731	264
Cash, cash equivalents, and restricted cash at beginning of year	47,047	26,316	26,052
Cash, cash equivalents, and restricted cash at end of year	164,864	47,047	26,316
Supplemental disclosure of cash flow information:
Cash paid for interest	1,663	63	81
Cash paid (refunded) for income taxes, net of (refunds) payments	891	(1)	59
Supplemental non-cash investing and financing activities:
Assets acquired under finance lease	828	43	738
Assets acquired under operating lease	123	11,735	0
Gain on extinguishment of PPP loan	$ 7,185	$ 0	$ 0