Derivatives Textuals (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Derivative [Line Items]
Servicing Asset at Fair Value, Changes in Fair Value Resulting from Changes in Valuation Inputs or Changes in Assumptions	$ 1,053,000,000	$ (835,000,000)	$ 280,000,000	$ (1,276,000,000)
Derivatives (Textual) [Abstract]
Derivative assets subject to enforceable master netting arrangements	67,600,000,000		67,600,000,000		$ 69,600,000,000
Derivative liabilities subject to enforceable master netting arrangements	73,800,000,000		73,800,000,000		75,000,000,000
Derivative assets not subject to enforceable master netting arrangements	16,300,000,000		16,300,000,000		18,900,000,000
Derivative liabilities not subject to enforceable master netting arrangements	7,300,000,000		7,300,000,000		8,800,000,000
Valuation adjustments for derivative assets	320,000,000		320,000,000		266,000,000
Valuation adjustments for derivative liabilities	94,000,000		94,000,000		56,000,000
Cash collateral netted against derivative assets	4,600,000,000		4,600,000,000		5,200,000,000
Cash collateral netted against derivative liabilities	5,700,000,000		5,700,000,000		4,600,000,000
Fair value asset derivatives, net	18,409,000,000		18,409,000,000		22,605,000,000
Time value component recognized as net interest income (expense) on forward derivatives excluded from the assessment of hedge effectiveness	(2,000,000)	0	(3,000,000)	0
Deferred net gains on derivatives in other comprehensive income			$ 992,000,000
Maximum length of time hedged in cash flow hedge			7 years
Change in value of derivatives excluded from assessment of cash flow hedge effectiveness	0	0	$ 0	0
Gains (losses) on derivatives used to hedge residential mortgage servicing rights	(946,000,000)	1,310,000,000	(65,000,000)	2,158,000,000
Aggregate fair value of derivatives used for economic hedges net asset (liability)	(190,000,000)		(190,000,000)		492,000,000
Aggregate fair value of derivative loan commitments net asset (liability)	36,000,000		36,000,000		98,000,000
Aggregate fair value of derivative instruments with credit-risk-related contingent features, net liability	11,600,000,000		11,600,000,000		13,600,000,000
Collateral for derivative instruments with credit-risk-related contingent features	8,700,000,000		8,700,000,000		10,500,000,000
Additional collateral for derivative instruments with credit-risk-related contingent features	2,900,000,000		2,900,000,000		3,100,000,000
Unreimbursed Direct Servicing Costs	109,000,000	$ 84,000,000	243,000,000	$ 232,000,000
Trading assets [Member]
Derivatives (Textual) [Abstract]
Fair value asset derivatives, net	15,100,000,000		15,100,000,000		16,900,000,000
Other assets [Member]
Derivatives (Textual) [Abstract]
Fair value asset derivatives, net	3,300,000,000		3,300,000,000		5,700,000,000
Interest rate contract [Member]
Derivatives (Textual) [Abstract]
Fair value asset derivatives, net	5,949,000,000		5,949,000,000		7,647,000,000
Foreign exchange contract [Member]
Derivatives (Textual) [Abstract]
Fair value asset derivatives, net	2,755,000,000		2,755,000,000		2,481,000,000
Designated as Hedging Instrument [Member] | Interest rate contract [Member]
Derivatives (Textual) [Abstract]
Certain derivatives combined for designation as a hedge on a single instrument	1,900,000,000		1,900,000,000		1,900,000,000
Designated as Hedging Instrument [Member] | Foreign exchange contract [Member]
Derivatives (Textual) [Abstract]
Certain derivatives combined for designation as a hedge on a single instrument	$ 4,100,000,000		$ 4,100,000,000		$ 2,700,000,000