DERIVATIVES - Effect of Customer Derivatives and Economic Hedges on Net Income (Details) - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income, Total		$ 3,000,000	$ 9,000,000	$ 7,000,000	$ 17,000,000
Other Income | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income, Total		(3,000,000)	0	6,000,000	0
Customer derivative contracts | Other Income | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income, Total	[1]	(9,000,000)	88,000,000	64,000,000	149,000,000
Customer derivative contracts | Other Income | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income, Total	[1]	18,000,000	2,000,000	(17,000,000)	6,000,000
Customer derivative contracts | Mortgage Banking Fees | Residential loan commitments
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income, Total	[2]	(7,000,000)	5,000,000	(7,000,000)	8,000,000
Economic hedges | Other Income | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income, Total	[1]	17,000,000	(82,000,000)	(51,000,000)	(135,000,000)
Economic hedges | Foreign Exchange and Trade Finance Fees | Foreign exchange contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income, Total	[3]	(19,000,000)	(1,000,000)	16,000,000	(7,000,000)
Economic hedges | Mortgage Banking Fees | Forward sale contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amounts Recognized in Noninterest Income, Total	[2]	$ 3,000,000	$ (3,000,000)	$ 2,000,000	$ (4,000,000)

[1] Reported in other income on the Consolidated Statements of Operations.

[2] Reported in mortgage banking fees on the Consolidated Statements of Operations.

[3] Reported in foreign exchange and trade finance fees on the Consolidated Statements of Operations.