Other Financial Information - Property and Equipment, Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Property and Equipment [Line Items]
Property and equipment, gross	$ 2,014.4	$ 1,983.0
Accumulated depreciation	(1,334.2)	(1,293.1)
Property and equipment, net	680.2	689.9
Depreciation expense	112.4	123.5	$ 137.7
Computers and equipment
Property and Equipment [Line Items]
Property and equipment, gross	1,008.9	990.0
Software
Property and Equipment [Line Items]
Property and equipment, gross	219.1	221.3
Leasehold improvements
Property and Equipment [Line Items]
Property and equipment, gross	182.6	185.9
Furniture and fixtures
Property and Equipment [Line Items]
Property and equipment, gross	44.7	45.3
Building and building improvements
Property and Equipment [Line Items]
Property and equipment, gross	294.6	292.8
Land and land improvements
Property and Equipment [Line Items]
Property and equipment, gross	243.6	243.6
Construction-in-process
Property and Equipment [Line Items]
Property and equipment, gross	$ 20.9	$ 4.1