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, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	$ (5,313)	$ (3,108)	$ (2,355)
Additions Charged to Costs and Expenses	(2,678)	(3,115)	(1,163)
Deduction	1,224	910	410
Balance at End of Year	(6,767)	(5,313)	(3,108)
Tax Valuation Allowance
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Year	(10,213)	(4,644)	(4,989)
Additions Charged to Costs and Expenses	(573)	(5,569)
Deduction			345
Balance at End of Year	$ (10,786)	$ (10,213)	$ (4,644)