Derivative Financial Instruments and Hedging Activities Schedule of Notional Amounts (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Notional amount	$ 19,128.6	$ 15,841.3
Swaps
Derivative [Line Items]
Notional amount	662.6	599.5
Futures, forwards and spot
Derivative [Line Items]
Notional amount	4,700.9	3,017.1
Written options
Derivative [Line Items]
Notional amount	7,940.1	6,393.9
Purchased options
Derivative [Line Items]
Notional amount	$ 5,825.0	$ 5,830.8