Revenue - Contract Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Deferred revenue	$ 40,092	$ 36,614	$ 29,745
Deferred revenue on consolidated balance sheet	$ 24,700	$ 19,700
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue recognized over remaining contract term	1 year
Remaining unearned revenue	$ 18,300
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction
Revenue recognized over remaining contract term
Remaining unearned revenue	$ 21,800