Loans and ACL (Schedule of Retail Credit Exposure, Credit Risk Profile Based on Payment Activity) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Loans and leases	$ 119,523	$ 115,917
Direct Retail Lending, Excluding Covered [Member]
Loans and leases	7,797	15,869
Direct Retail Lending, Excluding Covered [Member] | Performing [Member]
Loans and leases	7,748	15,760
Direct Retail Lending, Excluding Covered [Member] | Nonperforming [Member]
Loans and leases	49	109
Retail Revolving Credit, Excluding Covered [Member]
Loans and leases	2,391	2,403
Retail Revolving Credit, Excluding Covered [Member] | Performing [Member]
Loans and leases	2,391	2,403
Retail Revolving Credit, Excluding Covered [Member] | Nonperforming [Member]
Loans and leases	0	0
Retail Residential Mortgage-Nonguaranteed, Excluding Covered [Member]
Loans and leases	32,800	24,648
Retail Residential Mortgage-Nonguaranteed, Excluding Covered [Member] | Performing [Member]
Loans and leases	32,480	24,405
Retail Residential Mortgage-Nonguaranteed, Excluding Covered [Member] | Nonperforming [Member]
Loans and leases	320	243
Retail Sales Finance, Excluding Covered [Member]
Loans and leases	10,405	9,382
Retail Sales Finance, Excluding Covered [Member] | Performing [Member]
Loans and leases	10,400	9,377
Retail Sales Finance, Excluding Covered [Member] | Nonperforming [Member]
Loans and leases	5	5
Retail Other Lending Subsidiaries, Excluding Covered [Member]
Loans and leases	6,358	5,960
Retail Other Lending Subsidiaries, Excluding Covered [Member] | Performing [Member]
Loans and leases	6,316	5,910
Retail Other Lending Subsidiaries, Excluding Covered [Member] | Nonperforming [Member]
Loans and leases	$ 42	$ 50