Derivative Financial Instruments and Hedging Activities Schedule of Notional Amounts (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Notional amount	$ 14,988.3	$ 15,841.3
Swaps
Derivative [Line Items]
Notional amount	570.2	599.5
Futures, forwards and spot
Derivative [Line Items]
Notional amount	2,963.7	3,017.1
Written options
Derivative [Line Items]
Notional amount	5,906.0	6,393.9
Purchased options
Derivative [Line Items]
Notional amount	$ 5,548.4	$ 5,830.8