Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Operating activities:
Net loss	$ (70,730)	$ (236,649)
Adjustments to reconcile net loss to net cash used in operating activities:
Stock based compensation expense	5,810	5,368
Non-cash interest expense related to debt financing		562
Changes in operating assets and liabilities:
Prepaid expenses and other assets	5	(480)
Accounts payable	(4,178)	29,332
Accrued expenses	(5,091)	16,875
Deferred revenue	(2,514)	947
Net cash used in operating activities	(76,698)	(184,045)
Financing activities:
Net proceeds from issuance of common stock	41,843	159,915
Proceeds from exercise of stock options		1,965
Net proceeds from issuance of long-term debt		24,444
Principal payments on long-term debt	(25,006)
Net cash provided by financing activities	16,837	186,324
Net increase (decrease) in cash and cash equivalents	(59,861)	2,279
Cash and cash equivalents, beginning of period	70,016	67,737
Cash and cash equivalents, end of period	10,155	70,016
Supplemental cash flow disclosure:
Cash paid for interest	1,319	1,519
Supplemental disclosure of non-cash investing and financing activities:
Issuance of stock options in lieu of cash compensation		$ 168