Acquisitions - Additional Information (Detail) $ in Thousands	1 Months Ended	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) Company	Mar. 31, 2021 USD ($)
Business Acquisition [Line Items]
Goodwill	$ 179,118	$ 179,118	$ 179,417
Bright TALK [Member]
Business Acquisition [Line Items]
Fair value of cash consideration transferred	$ 151,000
Date of acquisition	Dec. 31, 2020
Business acquisition expected valuation term	1 year
Other Acquisitions [Member]
Business Acquisition [Line Items]
Fair value of cash consideration transferred		$ 25,000
Number of acquisitions | Company		2
Contingent consideration	$ 2,200	$ 2,200
Intangible assets	17,100	17,100
Assumed liabilities	3,500	3,500
Goodwill	$ 12,700	$ 12,700