Investment Securities (Summary) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	$ 43,425	$ 47,988
Securities available for sale, unrealized gains	1,330	1,138
Securities available for sale, unrealized losses	(236)	(519)
Securities available for sale, fair value	44,519	48,607
AFS to HTM Transfer Net Unrealized Gains In AOCI	141	111
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	43,070	47,554
Securities available for sale, unrealized gains	1,322	1,138
Securities available for sale, unrealized losses	(235)
Securities available for sale, fair value	44,157	48,174
Held-to-maturity securities, amortized cost	12,083
Held-to-maturity securities, unrealized gains	360	169
Held-to-maturity securities, unrealized losses	(27)
Held-to-maturity securities, fair value	12,416
Corporate Stocks And Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	355	434
Securities available for sale, fair value	362	433
US Treasury and Government Agencies Securities [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	5,210
Held-to-maturity securities, amortized cost	243
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	19,690
Held-to-maturity securities, amortized cost	5,712
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	5,102
Securities available for sale, unrealized gains		308
State and Municipal [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	1,865
Held-to-maturity securities, amortized cost	2,060
Other Debt Securities [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	1,795
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Held-to-maturity securities, unrealized losses		(91)
US Treasury and Government Agencies Securities [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	5,210	3,990
Securities available for sale, unrealized gains	160	135
Securities available for sale, unrealized losses	(3)
Securities available for sale, fair value	5,367	4,118
Held-to-maturity securities, amortized cost	243	239
Held-to-maturity securities, unrealized gains	28	8
Held-to-maturity securities, fair value	271	243
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)
Held-to-maturity securities, unrealized losses		(4)
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	19,690	22,669
Securities available for sale, unrealized gains	471	384
Securities available for sale, unrealized losses	(80)	(222)
Securities available for sale, fair value	20,081	22,831
Held-to-maturity securities, amortized cost	5,712
Held-to-maturity securities, unrealized gains	156
Held-to-maturity securities, unrealized losses	(19)
Held-to-maturity securities, fair value	5,849
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	5,102	5,457
Securities available for sale, unrealized gains	341
Securities available for sale, unrealized losses	(102)	(160)
Securities available for sale, fair value	5,341	5,605
Held-to-maturity securities, amortized cost	283
Held-to-maturity securities, unrealized gains	6
Held-to-maturity securities, fair value	288
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
Held-to-maturity securities, unrealized gains		71
Held-to-maturity securities, unrealized losses		(64)
Held-to-maturity securities, fair value		5,821
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
Held-to-maturity securities, unrealized losses	(1)	(4)
Held-to-maturity securities, fair value		289
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	591	632
Securities available for sale, unrealized gains	13	15
Securities available for sale, fair value	604	646
Held-to-maturity securities, amortized cost	1,204	1,251
Held-to-maturity securities, unrealized gains	63	49
Held-to-maturity securities, fair value	1,267	1,300
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	3,437	3,937
Securities available for sale, unrealized gains	125	123
Securities available for sale, unrealized losses	(4)	(18)
Securities available for sale, fair value	3,558	4,042
Held-to-maturity securities, amortized cost	1,273
Held-to-maturity securities, unrealized gains	24
Held-to-maturity securities, fair value	1,297
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		(1)
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
Held-to-maturity securities, unrealized gains		20
Held-to-maturity securities, unrealized losses		(5)
Held-to-maturity securities, fair value		1,702
Asset Backed Securities [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	5,380	5,754
Securities available for sale, unrealized gains	88	66
Securities available for sale, unrealized losses	(30)	(48)
Securities available for sale, fair value	5,438	5,772
Held-to-maturity securities, amortized cost	981
Held-to-maturity securities, unrealized gains	2	2
Held-to-maturity securities, unrealized losses	(7)
Held-to-maturity securities, fair value	976
Asset Backed Securities [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Held-to-maturity securities, amortized cost		1,009
Held-to-maturity securities, unrealized losses		(10)
Held-to-maturity securities, fair value		1,001
State and Municipal [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	1,865	2,609
Securities available for sale, unrealized gains	70	52
Securities available for sale, unrealized losses	(10)	(44)
Securities available for sale, fair value	1,925	2,617
Held-to-maturity securities, amortized cost	2,060	1,055
Held-to-maturity securities, unrealized gains	72	10
Held-to-maturity securities, fair value	2,132	1,061
State and Municipal [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Held-to-maturity securities, unrealized losses		(4)
Other Debt Securities [Member] | Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, amortized cost	1,795	2,506
Securities available for sale, unrealized gains	54	55
Securities available for sale, unrealized losses	(6)	(18)
Securities available for sale, fair value	1,843	2,543
Held-to-maturity securities, amortized cost	327	339
Held-to-maturity securities, unrealized gains	9	9
Held-to-maturity securities, fair value	336	348
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, unrealized losses		(518)
Held-to-maturity securities, amortized cost		11,687
Held-to-maturity securities, fair value		11,765
Corporate Stocks And Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Securities available for sale, unrealized gains	8
Securities available for sale, unrealized losses	$ (1)	$ (1)