Acquisitions - Schedule of Unaudited Pro Forma Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
MediaDonuts
Pro Forma:
Total revenue		$ 560,045
Net income (loss) attributable to common stockholders		$ (29,032)
Basic and diluted earnings per share:
Net income (loss) per share, attributable to common stockholders, basic		$ 0.34
Net income (loss) per share, attributable to common stockholders, diluted		$ 0.33
Weighted average common shares outstanding, basic		85,207,992
Weighted average common shares outstanding, diluted		87,694,395
365 Digital
Pro Forma:
Total revenue	$ 200,167	$ 528,406
Net income (loss) attributable to common stockholders	$ 12,225	$ (25,581)
Basic and diluted earnings per share:
Net income (loss) per share, attributable to common stockholders, basic	$ 0.14	$ 0.30
Net income (loss) per share, attributable to common stockholders, diluted	$ 0.14	$ 0.29
Weighted average common shares outstanding, basic	85,390,333	85,207,992
Weighted average common shares outstanding, diluted	88,315,732	87,694,395