Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities:
Net loss	$ (70,539)	$ (55,783)
Adjustments to reconcile net loss to net cash used for operating activities:
Depreciation, amortization, and impairment	2,964	3,443
Share-based compensation	6,819	6,581
Amortization of debt issuance costs and discounts	3,731	2,587
Interest expense related to the sale of future revenue	12,253	1,938
Loss on the extinguishment of debt	13,822	0
Other, net	(299)	188
Changes in operating assets and liabilities:
Trade receivables and other receivables, net	(5,353)	6,175
Inventories	(1,577)	398
Prepaid expenses and other assets	1,258	(7,953)
Accounts payable	1,225	(5,185)
Accrued expenses and other liabilities	(844)	2,980
Deferred revenue	3,561	(828)
Net cash used for operating activities	(32,979)	(45,459)
Cash flows from investing activities:
Capital expenditures	(913)	(517)
Net cash used for investing activities	(913)	(517)
Cash flows from financing activities:
Proceeds from issuance of common stock and warrant exercises, net	29,780	6,215
Proceeds from shares issued under employee stock purchase plan	158	0
Proceeds from exercise of stock options	185	0
Proceeds from sale of future revenue	0	50,000
Debt repayment	0	(22,500)
Payments for financing costs	0	(2,909)
Premium paid to retire debt	0	(2,250)
Payments for taxes on share-based compensation	(14)	(99)
Net cash provided by financing activities	30,109	28,457
Net decrease in cash and cash equivalents	(3,783)	(17,519)
Cash and cash equivalents:
Beginning of period	31,807	49,326
End of period	28,024	31,807
Supplemental disclosures of cash flow information:
Cash payments for interest	6,438	8,491
Debt issued in lieu of prepayment penalty	$ 0	$ 4,000