Consolidated Statements Of Comprehensive Income (Parenthetical) (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Statement of Comprehensive Income [Abstract]
Other comprehensive income/(loss), tax (benefit) expense	$ 6.7	$ (0.2)	$ 13.8	$ (3.7)
Reclassifications to earnings of realized gains/(losses) on available-for-sale securities			$ 0.0	$ 0.0