Notional and Fair Value Amounts of Client-related and Trading Derivative Financial Instruments (Detail) (Client Related and Trading, USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Notional Value	$ 262,922.5	$ 248,136.7
Fair Value Asset	4,255.0	2,967.5
Fair Value Liability	4,173.3	2,963.2
Foreign Exchange Contracts
Derivative [Line Items]
Notional Value	257,568.7	243,135.0
Fair Value Asset	4,149.5	2,844.7
Fair Value Liability	4,072.0	2,846.2
Interest Rate Contracts
Derivative [Line Items]
Notional Value	5,353.8	5,001.7
Fair Value Asset	105.5	122.8
Fair Value Liability	$ 101.3	$ 117.0