Acquisition, Goodwill and Acquired Intangible Assets - Schedule of Assets Acquired and Liabilities Assumed from Acquisition (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Apr. 30, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Goodwill	$ 126,705		$ 54,414
Alsid SAS
Business Acquisition [Line Items]
Accounts receivable		$ 4,105
Prepaid expenses and other assets		2,304
Intangible assets		31,400
Goodwill		72,291
Accounts payable, accrued expenses and accrued compensation		(3,794)
Deferred revenue		(3,699)
Deferred tax liabilities, net		(4,118)
Total purchase price		$ 98,489