Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits
Balance as of January 1	$ 1,923	$ 1,601	$ 1,408
Increases related to current tax positions	275	281	183
Increases related to prior year tax positions	19	150	20
Decreases related to prior year tax positions	(33)	(109)	(10)
Balance as of December 31	$ 2,184	$ 1,923	$ 1,601