Income Taxes - Deferred assets/liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets:
Allowance for doubtful accounts	$ 95	$ 113
Accrued compensation	4,529	3,119
Deferred revenue	8,331	3,724
Stock-based compensation	5,026	1,938
Federal tax credits	6,668	4,099
Net operating losses	46,173	26,996
State tax credits	2,086	1,640
Business interest limitation	10,450	9,829
Operating lease liabilities	4,848	0
Convertible Senior Notes	8,304	0
Other	3,172	1,942
Gross deferred tax assets	99,682	53,400
Valuation allowance	(31,512)	(3,016)
Total deferred tax assets	68,170	50,384
Deferred tax liabilities:
Prepaid items	(624)	(853)
Equipment and leasehold improvements	(168)	0
Deferred contract costs	(10,491)	(7,634)
Operating lease right-of-use assets	(4,047)	0
Intangibles and other	(59,670)	(46,898)
Other	(399)	0
Gross deferred tax liabilities	(75,399)	(55,385)
Net deferred tax liabilities	(7,229)	(5,001)
Non-current deferred tax assets	1,471	86
Non-current deferred tax liabilities	$ (8,700)	$ (5,087)