Investment Securities (Summary) (Details) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	$ 42,639,000,000	$ 47,988,000,000
Securities available for sale, unrealized gains	1,229,000,000	1,138,000,000
Securities available for sale, unrealized losses	(248,000,000)	(519,000,000)
Securities available for sale, fair value	43,620,000,000	48,607,000,000
AFS to HTM Transfer Net Unrealized Gains In AOCI	134,000,000	111,000,000
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	42,248,000,000	47,554,000,000
Securities available for sale, unrealized gains	1,222,000,000	1,138,000,000
Securities available for sale, unrealized losses	(247,000,000)
Securities available for sale, fair value	43,223,000,000	48,174,000,000
Held-to-maturity securities, amortized cost	11,419,000,000
Held-to-maturity securities, unrealized gains	321,000,000	169,000,000
Held-to-maturity securities, unrealized losses	(29,000,000)
Held-to-maturity securities, fair value	11,711,000,000
Corporate Stocks And Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost		434,000,000
Securities available for sale, fair value		433,000,000
US Treasury and Government Agencies Securities [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	5,176,000,000
Held-to-maturity securities, amortized cost	246,000,000
Residential Mortgage-backed Securities [Member] | Mortgage-backed Securities Agency [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	17,844,000,000
Held-to-maturity securities, amortized cost	5,427,000,000
Residential Mortgage-backed Securities [Member] | Mortgage-backed Securities Non-agency [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	4,904,000,000
Securities available for sale, unrealized gains		308,000,000
Held-to-maturity securities, amortized cost	276,000,000
Commercial Mortgage Backed Securities [Member] | Mortgage-backed Securities Agency [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	1,787,000,000
Held-to-maturity securities, amortized cost	1,252,000,000
Commercial Mortgage Backed Securities [Member] | Mortgage-backed Securities Non-agency [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	3,703,000,000
Held-to-maturity securities, amortized cost	1,068,000,000
State and Municipal [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	1,978,000,000
Held-to-maturity securities, amortized cost	2,053,000,000
Other Debt Securities [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	1,792,000,000
Held-to-maturity securities, amortized cost	325,000,000
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Held-to-maturity securities, unrealized losses		(91,000,000)
Residential And Commercial Mortgage-backed Securities [Member] | Mortgage-backed Securities Agency [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Quantifying Misstatement In Current Year Financial Statements Amount		1,100,000,000
US Treasury and Government Agencies Securities [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	5,176,000,000	3,990,000,000
Securities available for sale, unrealized gains	167,000,000	135,000,000
Securities available for sale, fair value	5,343,000,000	4,118,000,000
Held-to-maturity securities, amortized cost	246,000,000	239,000,000
Held-to-maturity securities, unrealized gains	30,000,000	8,000,000
Held-to-maturity securities, fair value	276,000,000	243,000,000
US Treasury and Government Agencies Securities [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, unrealized losses		(7,000,000)
Held-to-maturity securities, unrealized losses		(4,000,000)
Residential Mortgage-backed Securities [Member] | Mortgage-backed Securities Agency [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	17,844,000,000	21,556,000,000
Securities available for sale, unrealized gains	391,000,000	367,000,000
Securities available for sale, unrealized losses	(75,000,000)	(209,000,000)
Securities available for sale, fair value	18,160,000,000	21,714,000,000
Held-to-maturity securities, amortized cost	5,427,000,000
Held-to-maturity securities, unrealized gains	122,000,000
Held-to-maturity securities, unrealized losses	(21,000,000)
Held-to-maturity securities, fair value	5,528,000,000
Residential Mortgage-backed Securities [Member] | Mortgage-backed Securities Non-agency [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	4,904,000,000	5,457,000,000
Securities available for sale, unrealized gains	336,000,000
Securities available for sale, unrealized losses	(102,000,000)	(160,000,000)
Securities available for sale, fair value	5,138,000,000	5,605,000,000
Held-to-maturity securities, amortized cost	276,000,000
Held-to-maturity securities, unrealized gains	9,000,000
Held-to-maturity securities, fair value	285,000,000
Residential Mortgage-backed Securities [Member] | Debt Securities [Member] | Mortgage-backed Securities Agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Held-to-maturity securities, amortized cost		5,814,000,000
Held-to-maturity securities, unrealized gains		71,000,000
Held-to-maturity securities, unrealized losses		(64,000,000)
Held-to-maturity securities, fair value		5,821,000,000
Residential Mortgage-backed Securities [Member] | Debt Securities [Member] | Mortgage-backed Securities Non-agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Held-to-maturity securities, amortized cost		293,000,000
Held-to-maturity securities, unrealized losses	0	(4,000,000)
Held-to-maturity securities, fair value		289,000,000
Commercial Mortgage Backed Securities [Member] | Mortgage-backed Securities Agency [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	1,787,000,000	1,745,000,000
Securities available for sale, unrealized gains	22,000,000	32,000,000
Securities available for sale, unrealized losses	(17,000,000)
Securities available for sale, fair value	1,792,000,000	1,763,000,000
Held-to-maturity securities, amortized cost	1,252,000,000	1,251,000,000
Held-to-maturity securities, unrealized gains	50,000,000	49,000,000
Held-to-maturity securities, fair value	1,302,000,000	1,300,000,000
Commercial Mortgage Backed Securities [Member] | Mortgage-backed Securities Non-agency [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	3,703,000,000	3,937,000,000
Securities available for sale, unrealized gains	95,000,000	123,000,000
Securities available for sale, unrealized losses	(10,000,000)	(18,000,000)
Securities available for sale, fair value	3,788,000,000	4,042,000,000
Held-to-maturity securities, amortized cost	1,068,000,000
Held-to-maturity securities, unrealized gains	14,000,000
Held-to-maturity securities, unrealized losses	(1,000,000)
Held-to-maturity securities, fair value	1,081,000,000
Commercial Mortgage Backed Securities [Member] | Debt Securities [Member] | Mortgage-backed Securities Agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, unrealized losses		(14,000,000)
Commercial Mortgage Backed Securities [Member] | Debt Securities [Member] | Mortgage-backed Securities Non-agency [Member]
Schedule of Available-for-sale Securities [Line Items]
Held-to-maturity securities, amortized cost		1,687,000,000
Held-to-maturity securities, unrealized gains		20,000,000
Held-to-maturity securities, unrealized losses		(5,000,000)
Held-to-maturity securities, fair value		1,702,000,000
Asset Backed Securities [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	5,064,000,000	5,754,000,000
Securities available for sale, unrealized gains	87,000,000	66,000,000
Securities available for sale, unrealized losses	(28,000,000)	(48,000,000)
Securities available for sale, fair value	5,123,000,000	5,772,000,000
Held-to-maturity securities, amortized cost	772,000,000
Held-to-maturity securities, unrealized gains	2,000,000	2,000,000
Held-to-maturity securities, unrealized losses	(7,000,000)
Held-to-maturity securities, fair value	767,000,000
Asset Backed Securities [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Held-to-maturity securities, amortized cost		1,009,000,000
Held-to-maturity securities, unrealized losses		(10,000,000)
Held-to-maturity securities, fair value		1,001,000,000
State and Municipal [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	1,978,000,000	2,609,000,000
Securities available for sale, unrealized gains	80,000,000	52,000,000
Securities available for sale, unrealized losses	(8,000,000)	(44,000,000)
Securities available for sale, fair value	2,050,000,000	2,617,000,000
Held-to-maturity securities, amortized cost	2,053,000,000	1,055,000,000
Held-to-maturity securities, unrealized gains	89,000,000	10,000,000
Held-to-maturity securities, fair value	2,142,000,000	1,061,000,000
State and Municipal [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Held-to-maturity securities, unrealized losses		(4,000,000)
Other Debt Securities [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	1,792,000,000	2,506,000,000	[1],[2]
Securities available for sale, unrealized gains	44,000,000	55,000,000
Securities available for sale, unrealized losses	(7,000,000)	(18,000,000)
Securities available for sale, fair value	1,829,000,000	2,543,000,000
Held-to-maturity securities, amortized cost	325,000,000	339,000,000
Held-to-maturity securities, unrealized gains	5,000,000	9,000,000
Held-to-maturity securities, fair value	330,000,000	348,000,000
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, unrealized losses		(518,000,000)
Held-to-maturity securities, amortized cost		11,687,000,000
Held-to-maturity securities, fair value		11,765,000,000
Corporate Stocks And Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	391,000,000
Securities available for sale, unrealized gains	7,000,000
Securities available for sale, unrealized losses	(1,000,000)	(1,000,000)
Securities available for sale, fair value	$ 397,000,000

[1] See accompanying Notes To Consolidated Financial Statements.

[2] (b) Includes the impact of the consolidation of a variable interest entity as of March 31, 2013.