Acquisitions - Schedule of Unaudited Pro Forma Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021
MediaDonuts
Pro Forma:
Total revenue	$ 190,456	$ 348,933
Net income (loss) attributable to common stockholders	$ 9,459	$ (16,048)
Basic and diluted earnings per share:
Net income (loss) per share, attributable to common stockholders, basic	$ 0.11	$ 0.19
Net income (loss) per share, attributable to common stockholders, diluted	$ 0.11	$ 0.18
Weighted average common shares outstanding, basic	85,188,182	85,115,310
Weighted average common shares outstanding, diluted	87,777,039	87,382,215
365 Digital
Pro Forma:
Total revenue	$ 179,008	$ 328,239
Net income (loss) attributable to common stockholders	$ 7,904	$ (13,356)
Basic and diluted earnings per share:
Net income (loss) per share, attributable to common stockholders, basic	$ 0.09	$ 0.16
Net income (loss) per share, attributable to common stockholders, diluted	$ 0.09	$ 0.15
Weighted average common shares outstanding, basic	85,188,182	85,115,310
Weighted average common shares outstanding, diluted	87,777,039	87,382,215