Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
CASH FLOWS USED IN OPERATING ACTIVITIES:
Net loss	$ (32,559)	$ (81,534)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	494	945
Amortization of premium/discount on marketable securities, net	19	132
Amortization of debt discount and debt issuance costs	771	8,725
Stock-based compensation	11,113	13,299
Gain on extinguishment of debt	(1,960)	0
Gain on the lease termination	901	0
Changes in operating assets and liabilities:
Inventory	(2,136)	(583)
Accounts receivable, net	(3,328)	5,390
Prepaid expenses	1,877	4,210
Other current assets	(15,959)	(992)
Operating lease right of use assets	667	1,027
Other long-term assets	(967)	0
Accounts payable	4,637	5,688
Deferred revenue	(1,000)	0
Accrued expenses and other current liabilities	6,327	(1,274)
Lease liability, operating leases	(1,199)	(1,102)
Net cash used in operating activities	(34,104)	(46,069)
CASH FLOWS PROVIDED BY INVESTING ACTIVITIES:
Purchases of marketable securities	0	(39,907)
Sales and maturities of marketable securities	23,240	61,400
Net cash provided by investing activities	23,240	21,493
CASH FLOWS PROVIDED BY FINANCING ACTIVITIES:
Proceeds from exercise of stock options	3,804	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	678	990
Net cash provided by financing activities	18,601	10,929
NET INCREASE IN CASH, CASH EQUIVALENTS, AND RESTRICTED CASH	7,737	(13,647)
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH AT BEGINNING OF PERIOD	92,003	70,453
CASH, CASH EQUIVALENTS, AND RESTRICTED CASH AT END OF PERIOD	99,740	56,806
SUPPLEMENTAL DISCLOSURES:
Cash paid for interest	7,622	4,818
Cash paid for amounts included in the measurement of operating lease liabilities	1,340	1,175
Right of use assets obtained in exchange for operating lease liability	$ 332	$ 1,110