Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allowance for doubtful accounts
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 416	$ 1,092	$ 1,117
Additions	0	0	514
Deductions (Charge-offs)	(140)	(676)	(539)
Balance at End of Year	276	416	1,092
Valuation allowance for deferred tax assets
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	46,517	39,932	33,876
Additions	6,734	6,585	6,056
Deductions (Charge-offs)	0	0	0
Balance at End of Year	$ 53,251	$ 46,517	$ 39,932