Fair Value Disclosures (Carrying Amounts and Fair Values of Financial Assets and Liabilities Not Recorded at Fair Value) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
HTM securities, amortized cost	$ 18,101	$ 13,594
Deposits	127,475	133,075
Long-term debt	21,493	19,114
Carrying Amount [Member]
HTM securities, amortized cost	18,101	13,594
Loans and leases,net of ALLL (excluding covered)	112,264	109,419
Covered loans, net of ALLL	1,921	3,166
FDIC loss share receivable	843	1,106
Deposits	127,475	133,075
FDIC loss share payable	669	627
Long-term debt	21,493	19,114
Estimate of Fair Value, Fair Value Disclosure [Member]
HTM securities, amortized cost	17,530	13,848
Loans and leases,net of ALLL (excluding covered)	112,261	109,621
Covered loans, net of ALLL	2,200	3,661
FDIC loss share receivable	464	751
Deposits	127,810	133,377
FDIC loss share payable	652	602
Long-term debt	22,313	20,676
Level 2 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
HTM securities, amortized cost	17,491	13,810
Loans and leases,net of ALLL (excluding covered)	0	0
Covered loans, net of ALLL	0	0
FDIC loss share receivable	0	0
Deposits	127,810	133,377
FDIC loss share payable	0	0
Long-term debt	22,313	20,676
Level 3 [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
HTM securities, amortized cost	39	38
Loans and leases,net of ALLL (excluding covered)	112,261	109,621
Covered loans, net of ALLL	2,200	3,661
FDIC loss share receivable	464	751
Deposits	0	0
FDIC loss share payable	652	602
Long-term debt	$ 0	$ 0