Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 218.5	$ 208.2	$ 568.4	$ 549.4
Other comprehensive income (loss), net of income tax:
Foreign currency translation adjustments	39.6	(48.1)	23.4	(17.7)
Unrealized holding gains (losses) on available-for-sale financial investments	6.0	(0.9)	5.0	(2.6)
Realized gains on available-for-sale financial investments	(1.3)	0.0	(1.3)	0.0
Post-retirement benefit obligations	(0.1)	0.0	0.1	(0.1)
Comprehensive income	262.7	159.2	595.6	529.0
Comprehensive income allocated to participating securities	(1.1)	(1.1)	(3.0)	(2.7)
Comprehensive income allocated to common stockholders, net of income tax	$ 261.6	$ 158.1	$ 592.6	$ 526.3