Commitments, Contingencies And Guarantees (Guarantees) (Details) - Notional [Member] $ in Millions	Dec. 31, 2016 USD ($)
Derivative Contracts - Non-Credit Related [Member]
Guarantor Obligations [Line Items]
2017	$ 18,838.6
2018	820.4
2019 and 2020	0.0
2021 and 2022	0.0
2023 and Later	421.8
Maximum Payout	20,080.8
Written Derivative Contracts - Credit Related [Member]
Guarantor Obligations [Line Items]
2017	0.0
2018	52.2
2019 and 2020	24.6
2021 and 2022	360.8
2023 and Later	0.0
Maximum Payout	437.6
Derivative [Member]
Guarantor Obligations [Line Items]
2017	18,838.6
2018	872.6
2019 and 2020	24.6
2021 and 2022	360.8
2023 and Later	421.8
Maximum Payout	$ 20,518.4