Leases - Components of Lease Expense and Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Operating lease expense	$ 247	$ 258	$ 735	$ 1,112
Finance lease expense:
Amortization of right-of-use assets	4	4	11	13
Interest on lease liabilities	2	5	9	14
Total finance lease expense	6	9	20	27
Short-term lease expense	15	57	44	145
Total lease expense	268	324	799	1,284
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	380	317	1,107	2,312
Operating cash flows from finance leases	10	5	62	13
Financing cash flows from finance leases	$ 2	$ 51	$ 8	$ 152