Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Statement of Comprehensive Income [Abstract]
Net income	$ 534.5	$ 433.4
Other comprehensive income (loss):
Change in foreign currency translation	0.0	3.4
Change in unrealized gains (losses) on investments	(2.9)	(0.3)
Less: tax benefit related to items of other comprehensive income (loss)	(0.6)	(0.1)
Other comprehensive income (loss)	(2.3)	3.2
Comprehensive income	$ 532.2	$ 436.6