Consolidated Statements Of Comprehensive Income (Parenthetical) (Unaudited) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Other comprehensive income/(loss), tax	$ 10.1	$ (2.3)
Reclassifications to earnings on available-for-sale securities	0.0	0.0
Reclassifications to earnings of gains on cash flow hedging instruments	1.5	$ 0.5
ASU 2018-02 [Member]
Reclassification to retained earnings related to cash flow hedges and investment portfolio credit risk	$ 3.1

Amount after tax of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).

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