Revenue (Tables)

12 Months Ended

Dec. 31, 2021

Revenue from Contract with Customer [Abstract]

Summary of revenue

The following table presents a summary of revenue:

	Year Ended December 31,
(in thousands)	2021		2020		2019
Subscription revenue	$	476,023	$	377,354	$	290,549
Perpetual license and maintenance revenue	50,333		50,594		54,173
Professional services and other revenue	14,774		12,273		9,864
Revenue	$	541,130	$	440,221	$	354,586

Activity of deferred contract costs

The following summarizes the activity of deferred incremental costs of obtaining a contract:

	Year Ended December 31,
(in thousands)	2021		2020
Beginning balance	$	78,876	$	72,265
Capitalization of contract acquisition costs	58,196		38,756
Amortization of deferred contract acquisition costs	(37,123)		(32,145)
Ending balance	$	99,949	$	78,876