Summary of Significant Accounting Policies - Revenue and Net income (loss) per share (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Summary of Significant Accounting Policies
Unsatisfied performance obligation	$ 91,943
Revenue recognition	286,104	$ 243,530	$ 208,511
Software licenses transferred at a point in time
Summary of Significant Accounting Policies
Revenue recognition	40,167	36,388	35,261
Software licenses transferred over time
Summary of Significant Accounting Policies
Revenue recognition	46,658	37,075	33,080
Service revenues earned over time
Summary of Significant Accounting Policies
Revenue recognition	$ 199,279	$ 170,067	$ 140,170
Minimum
Contract Balances
Subscription term	1 year
Maximum
Contract Balances
Subscription term	3 years