Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Operating activities:
Net loss	$ (51,427)	$ (136,370)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock based compensation expense	3,178	2,381
Non-cash interest expense related to debt financing	380	187
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(1,358)	(629)
Accounts payable	11,967	21,878
Accrued expenses	(5,487)	5,750
Deferred revenue	(2,072)	3,019
Net cash used in operating activities	(44,819)	(103,784)
Financing activities:
Net proceeds from issuance of common stock	21,849	130,278
Proceeds from exercise of stock options		1,861
Net proceeds from issuance of long-term debt		24,444
Net cash provided by financing activities	21,849	156,583
Net increase (decrease) in cash and cash equivalents	(22,970)	52,799
Cash and cash equivalents, beginning of period	70,016	67,737
Cash and cash equivalents, end of period	47,046	120,536
Supplemental cash flow disclosure:
Cash paid for interest	$ 943	$ 393