Goodwill and Intangible Assets, Net - Acquisition-Related Intangible Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 1,347.4	$ 1,222.7
Accumulated Amortization	(541.1)	(384.6)
Net Book Value	806.3	838.1
Developed Technology [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	1,082.9	972.2
Accumulated Amortization	(475.0)	(346.5)
Net Book Value	607.9	625.7
Trademarks, Branding and Domain Names [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	219.8	208.5
Accumulated Amortization	(55.5)	(35.5)
Net Book Value	164.3	173.0
Developer and Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	44.7	42.0
Accumulated Amortization	(10.6)	(2.6)
Net Book Value	$ 34.1	$ 39.4