Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of the beginning and ending balance of unrecognized tax benefits
Balance at beginning of year	$ 10,044	$ 9,799	$ 9,127
(Decrease) increase in unrecognized tax benefits as a result of tax positions taken during a prior period			215
(Decrease) / increase in unrecognized tax benefits as a result of tax positions taken during a prior period	(546)	(502)
Reductions to unrecognized tax benefits as a result of a lapse of the applicable statute of limitations	(472)		(334)
Increases in unrecognized tax benefits as a result of tax positions taken during the current period	935	747	791
Balance at end of year	9,961	10,044	9,799
Recorded as other long-term liability		472	409
Recorded as a decrease in deferred tax assets	9,961	9,572	9,390
Unrecognized tax benefits	$ 9,961	$ 10,044	$ 9,799