Description of Business and Summary of Significant Accounting Policies - Schedule of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash and cash equivalents	$ 10,374	$ 2,406	$ 1,771
Restricted cash, included in Prepaid expenses and other current assets	2,282	0	0
Cash and cash equivalents	$ 12,656	$ 2,406	$ 1,771	$ 1,912