Fair Value Disclosures (Schedule of Assets and Liabilities Measured at Fair Value) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Trading securities	$ 381	$ 497
AFS securities	22,104	25,137
LHFS	1,222	3,761
Residential MSRs	1,047	627	563	830
Private equity and similar investments	291	323
Assets measured at fair value	25,909	31,795
Short-term borrowings	84	98
Total liabilities	1,054	1,535
Level 1 [Member]
Trading securities	256	302
LHFS	0	0
Residential MSRs	0	0
Private equity and similar investments	0	0
Assets measured at fair value	266	304
Short-term borrowings	0	0
Total liabilities	0	0
Level 2 [Member]
Trading securities	125	194
LHFS	1,222	3,761
Residential MSRs	0	0
Private equity and similar investments	0	0
Assets measured at fair value	23,441	29,491
Short-term borrowings	84	98
Total liabilities	1,040	1,534
Level 3 [Member]
Trading securities	0	1
LHFS	0	0
Residential MSRs	1,047	627
Private equity and similar investments	291	323
Assets measured at fair value	2,202	2,000
Short-term borrowings	0	0
Total liabilities	14	1
U.S. Treasury Securities
AFS securities	595	281
U.S. Treasury Securities | Level 2 [Member]
AFS securities	595	281
GSE Securities
AFS securities		9
GSE Securities | Level 2 [Member]
AFS securities		9
MBS Issued by GSE
AFS securities	17,929	20,930
MBS Issued by GSE | Level 2 [Member]
AFS securities	17,929	20,930
States and Political Subdivisions [Member]
AFS securities	1,851	2,011
States and Political Subdivisions [Member] | Level 2 [Member]
AFS securities	1,851	2,011
Non-Agency MBS [Member]
AFS securities	291	312
Non-Agency MBS [Member] | Level 2 [Member]
AFS securities	291	312
Other Securities [Member]
AFS securities	45	3
Other Securities [Member] | Level 1 [Member]
AFS securities	10	2
Other Securities [Member] | Level 2 [Member]
AFS securities	35	1
Covered Securities [Member]
AFS securities	1,393	1,591
Covered Securities [Member] | Level 2 [Member]
AFS securities	532	597
Covered Securities [Member] | Level 3 [Member]
AFS securities	861	994
Interest Rate Contract [Member]
Derivative assets	862	1,446
Derivative liabilities	967	1,434
Interest Rate Contract [Member] | Level 2 [Member]
Derivative assets	859	1,391
Derivative liabilities	953	1,433
Interest Rate Contract [Member] | Level 3 [Member]
Derivative assets	3	55
Derivative liabilities	14	1
Foreign Exchange Contracts [Member]
Derivative assets	2	4
Derivative liabilities	3	3
Foreign Exchange Contracts [Member] | Level 2 [Member]
Derivative assets	2	4
Derivative liabilities	$ 3	$ 3