Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
CASH FLOWS USED IN OPERATING ACTIVITIES:
Net loss	$ (54,592)	$ (87,823)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	773	1,616
Amortization of premium/discount on marketable securities, net	19	237
Amortization of debt discount and debt issuance costs	1,187	13,313
Impairment loss on operating lease right of use assets	0	1,510
Stock-based compensation	17,197	19,821
Gain on extinguishment of debt	(1,960)	0
Gain on the lease termination	(901)	0
Changes in operating assets and liabilities:
Inventory	(2,430)	(2,183)
Accounts receivable, net	(6,235)	2,114
Prepaid expenses	4,148	785
Other current assets	2,432	(16,232)
Operating lease right of use assets	899	1,472
Other long-term assets	(1,659)	30
Accounts payable	3,623	9,737
Deferred revenue	(1,000)	0
Accrued expenses and other current liabilities	16,008	10,632
Lease liability, operating leases	(1,704)	(1,629)
Net cash used in operating activities	(24,195)	(46,600)
CASH FLOWS PROVIDED BY INVESTING ACTIVITIES:
Purchases of marketable securities	0	(39,916)
Sales and maturities of marketable securities	23,240	86,900
Net cash provided by investing activities	23,240	46,984
CASH FLOWS PROVIDED BY FINANCING ACTIVITIES:
Proceeds from exercise of stock options	3,805	0
Proceeds from issuance of term loan, net of issuance costs	122,687	9,939
Repurchase of convertible notes	(108,568)	0
Proceeds from issuance of shares under employee stock purchase plan	1,154	1,621
Net cash provided by financing activities	19,078	11,560
NET INCREASE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	18,123	11,944
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH AT BEGINNING OF PERIOD	92,003	70,453
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH AT END OF PERIOD	110,126	82,397
SUPPLEMENTAL DISCLOSURES:
Cash paid for interest	13,569	9,658
Cash paid for amounts included in the measurement of operating lease liabilities	1,858	1,932
Right of use assets obtained in exchange for operating lease liability	$ 544	$ 1,110