Consolidated Statements Of Comprehensive Income (Parenthetical) (Unaudited) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Statement Of Income And Comprehensive Income [Abstract]
Other comprehensive income/(loss), tax	$ 20.8	$ 6.4
Reclassifications to earnings of realized gains/(losses) on available-for-sale securities	$ 0.0	$ 0.0

Amount of tax expense (benefit) allocated to other comprehensive income (loss).

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+ Details