Schedule II - Valuation and Qualifying Accounts (Details) - Allowance for doubtful accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 1,081	$ 1,079	$ 1,254
Other	0	2	0
Additions	12	0	21
Deductions	(694)	0	(196)
Balance at end of year	$ 399	$ 1,081	$ 1,079