Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities
Net income (loss)	$ (31,948)	$ (31,534)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization	436	443
Stock-based compensation expense	1,449	1,345
Warrant issuance costs	0
Warrant liability fair value adjustment	3,615	(1,410)
Changes in assets and liabilities
Prepaid expenses and other assets	597	(1,138)
Accounts payable	(4,872)	2,043
Deferred revenue	(2,389)	(2,707)
Accrued and other liabilities	(2,296)	924
Net cash used in operating activities	(35,408)	(31,911)
Cash flows from financing activities
Proceeds from issuance of common stock in connection with employee benefit plans	25	26
Net cash provided by financing activities	25	19,320
Net change in cash, cash equivalents, and restricted cash	(35,383)	(12,591)
Cash, cash equivalents, and restricted cash at beginning of period	56,134	61,855
Cash, cash equivalents, and restricted cash at end of period	20,751	49,264
Supplemental disclosure of noncash items
Warrant liability reclass to additional-paid-in-capital upon warrant exercise	0	8,590
Direct Offering [Member]
Cash flows from financing activities
Proceeds from issuance of common stock and common stock warrants, net of issuance costs	0	19,171
At-the-market Offering [Member]
Cash flows from financing activities
Proceeds from issuance of common stock in at the market offering	$ 0	$ 123