Leases - Schedule of Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Operating Leases
Operating lease right-of-use assets	$ 419	$ 794
Restructured lease right-of-use assets	0	107
Operating lease right-of-use assets, total	419	901
Operating lease liabilities	505	916
Restructured lease liabilities	0	168
Operating lease liabilities, total	505	1,084
Finance Leases
Property and equipment	13	13
Allowances for depreciation	(11)	(9)
Finance lease assets, net	2	4
Finance lease liabilities	$ 1	$ 4