Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 14,521	$ (23,601)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	953	721
Share in net loss of equity method investment	47	5,523
Stock-based compensation	9,510	5,139
Amortization of right-of-use assets	767	405
Accretion of discount on available-for-sale securities	210	379
Amortization of debt issuance costs	153	167
Changes in operating assets and liabilities:
Accounts receivable	(10,407)	(7,924)
Inventory	(10,090)	(3,308)
Prepaid expenses and other current assets	600	(135)
Other assets	(119)	48
Accounts payable	4,911	1,782
Accrued and other current liabilities	(9,051)	3,799
Lease liabilities	(68)	(298)
Net cash provided by (used in) operating activities	1,937	(17,303)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of available-for-sale securities	(42,128)	(15,263)
Proceeds from maturities of available-for-sale securities	18,000	46,400
Purchase of property and equipment	(3,286)	(4,051)
Net cash (used in) provided by investing activities	(27,414)	27,086
CASH FLOWS FROM FINANCING ACTIVITIES:
Payments of taxes withheld on net settled vesting of restricted stock units	(6)	(5,114)
Proceeds from stock option exercises	391	773
Proceeds from issuance of common stock under employee stock purchase plan	2,135	1,141
Net cash provided by (used in) financing activities	2,520	(3,200)
Net (decrease) increase in cash, cash equivalents and restricted cash	(22,957)	6,583
Cash, cash equivalents and restricted cash at beginning of period	90,874	51,873
Cash, cash equivalents and restricted cash equivalents at end of period	67,917	58,456
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Interest paid	144	144
Income tax paid	78	15
NON-CASH INVESTING AND FINANCING ACTIVITIES:
Right-of-use asset obtained in exchange for lease liability	0	48
Property and equipment purchases included in accounts payable and accrued liabilities	3,159	3,104
Equity method investment obtained in exchange for related party contract liability	0	12,273
Transfer of fixed assets to inventory	$ 44	$ 116