Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss				$ (18,226)	$ (19,136)
Adjustments to reconcile net loss to net cash used in operating activities:
Net amortization of premiums (accretion of discounts) on marketable securities				(1)	(7)
Depreciation and amortization expense				97	375
Non-cash lease expense				1,967	2,518
Stock/equity-based compensation expense				2,276	2,666
Other non-cash expense				0	55
Non-cash interest expense				36	284
Loss (gain) on debt extinguishment	$ 0		$ 0	200	(1,134)
Impairment of right-of-use asset		$ 3,900		3,901	0
Loss on sale of property and equipment				20	63
Changes in operating assets and liabilities:
Accounts receivable				(5,000)
Prepaid expenses and other current assets				(668)	(164)
Deposits				366
Operating lease liabilities				(2,076)	(2,157)
Accounts payable				(240)	(5,573)
Accrued expenses and other current liabilities				(3,090)	(4,047)
Deferred revenue				(2,680)	(5,646)
Net cash used in operating activities				(13,118)	(31,903)
Cash flows from investing activities:
Purchases of marketable securities				0	(9,869)
Proceeds from sales and maturities of marketable securities				1,400	6,075
Purchases of property and equipment				(53)	(90)
Proceeds from sale of property and equipment				263
Net cash provided by (used in) investing activities				1,610	(3,884)
Cash flows from financing activities:
Proceeds from at the market offering				383	1,313
Proceeds from exercise of stock options				0	57
Proceeds from issuance of short-term borrowings				1,742
Payments of principal portion of long-term debt				(929)
Payments of final payoff of long term debt				(11,803)
Payments of debt issuance costs related to long-term debt				0	(103)
Payments of short-term borrowings				(1,164)
Payments of finance lease obligations				(27)	(108)
Net cash provided by (used in) financing activities				(11,798)	1,159
Net decrease in cash, cash equivalents and restricted cash				(23,306)	(34,628)
Cash, cash equivalents and restricted cash at beginning of period		$ 36,030		36,030	82,885
Cash, cash equivalents and restricted cash at end of period	$ 12,724		$ 48,257	12,724	48,257	$ 82,885
Supplemental cash flow information:
Cash paid for interest				$ 400	$ 660