Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Statement Of Cash Flows [Abstract]
Related parties prepaid expenses and other assets current	$ 82	$ 0
Related parties accounts payable and accrued expenses	$ 1,251	$ 238