Share-Based Payments - SOP 2015 (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Stock Options
Additional disclosures
Share-based compensation expense	$ 100	$ 51	$ 200	$ 65
Stock Option Plan 2015
Options
Outstanding at beginning of year (in shares)			202,374
Forfeited (in shares)			(32,824)
Outstanding at end of year (in shares)	169,550		169,550
Vested and exercisable at end of year (in shares)	169,141		169,141
Weighted average exercise price in $ per share
Outstanding balance at beginning of year (in dollars per share)			$ 82.71
Forfeited (in dollars per share)			88.93
Outstanding balance at end of year (in dollars per share)	$ 81.51		81.51
Vested and exercisable balance at end of year (in dollars per share)	$ 81.48		$ 81.48
Stock Option Plan 2015 | Stock Options
Share-Based Payments
Vesting period			4 years
Additional disclosures
Share-based compensation expense	$ 38,000	$ 300	$ 169,000	$ 600
Weighted-average remaining contractual life			4 years 10 months 24 days
Total unrecognized compensation related to unvested options	$ 3		$ 3
Recognition period			1 month 6 days
Stock Option Plan 2015 | Stock Options | Vesting period, year one
Share-Based Payments
Percentage that vests during the period			25.00%
Stock Option Plan 2015 | Stock Options | Vesting period, years 2-4
Share-Based Payments
Percentage that vests during the period			75.00%
Monthly vesting percentage			2.083%
Stock Option Plan 2015 | Maximum | Stock Options
Share-Based Payments
Exercise period			10 years