Leases - Summary of Components of Total Lease Expense and Operating Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Lease expense:
Operating lease expense	$ 321	$ 321	$ 962	$ 983
Variable lease expense	37	167	108	239
Total lease expense	358	488	1,070	1,222
Cash paid:
Cash paid reducing operating lease liabilities	$ 356	$ 484	$ 1,061	$ 1,206