Acquisitions - Summary of Purchase Price Allocation (Detail) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	Nov. 01, 2021	Jul. 01, 2021	Oct. 13, 2020
Business Acquisition [Line Items]
Goodwill	$ 86,715	$ 71,708
Cisneros Interactive
Business Acquisition [Line Items]
Cash					$ 8,700
Accounts receivable					50,500
Other assets					8,300
Intangible assets subject to amortization					41,700
Goodwill					10,500
Current liabilities					(48,100)
Deferred tax					(10,900)
Redeemable noncontrolling interest					$ (30,800)
MediaDonuts
Business Acquisition [Line Items]
Cash				$ 4,300
Accounts receivable				9,900
Other assets				1,800
Intangible assets subject to amortization				22,800
Goodwill				13,200
Current liabilities				(10,100)
Deferred tax				(4,000)
Debt				$ (1,700)
365 Digital
Business Acquisition [Line Items]
Cash			$ 500
Accounts receivable			1,100
Intangible assets subject to amortization			2,200
Goodwill			3,700
Current liabilities			(1,400)
Deferred tax			$ (600)