Securities (Details 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	$ 12,290	$ 3,112
Securities available for sale, 12 months or more, Fair Value	1,046	1,146
Securities available for sale, Fair Value, Total	13,336	4,258
Securities available for sale, Less than 12 months, Unrealized Losses	415	84
Securities available for sale, 12 months or more, Unrealized Losses	38	54
Securities available for sale, Unrealized Losses, Total	453	138
Residential mortgage-backed securities, U.S. government agency and government-sponsored agencies
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	8,508	1,152
Securities available for sale, 12 months or more, Fair Value	147	13
Securities available for sale, Fair Value, Total	8,655	1,165
Securities available for sale, Less than 12 months, Unrealized Losses	293	3
Securities available for sale, 12 months or more, Unrealized Losses	3
Securities available for sale, Unrealized Losses, Total	296	3
Residential mortgage-backed securities, Privately issued
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	72	32
Securities available for sale, 12 months or more, Fair Value	18	137
Securities available for sale, Fair Value, Total	90	169
Securities available for sale, Less than 12 months, Unrealized Losses	2
Securities available for sale, 12 months or more, Unrealized Losses		10
Securities available for sale, Unrealized Losses, Total	2	10
Commercial mortgage-backed securities
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	1,274	675
Securities available for sale, 12 months or more, Fair Value	58
Securities available for sale, Fair Value, Total	1,332	675
Securities available for sale, Less than 12 months, Unrealized Losses	80	6
Securities available for sale, 12 months or more, Unrealized Losses	5
Securities available for sale, Unrealized Losses, Total	85	6
Collateralized loan obligations
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	1,879	168
Securities available for sale, 12 months or more, Fair Value	10	980
Securities available for sale, Fair Value, Total	1,889	1,148
Securities available for sale, Less than 12 months, Unrealized Losses	21	1
Securities available for sale, 12 months or more, Unrealized Losses	1	43
Securities available for sale, Unrealized Losses, Total	22	44
Asset-backed and other
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value		32
Securities available for sale, 12 months or more, Fair Value	1	3
Securities available for sale, Fair Value, Total	1	35
Asset Liability Management securities
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	11,733	2,059
Securities available for sale, 12 months or more, Fair Value	234	1,133
Securities available for sale, Fair Value, Total	11,967	3,192
Securities available for sale, Less than 12 months, Unrealized Losses	396	10
Securities available for sale, 12 months or more, Unrealized Losses	9	53
Securities available for sale, Unrealized Losses, Total	405	63
Other debt securities, Direct bank purchase bonds
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	537	1,019
Securities available for sale, 12 months or more, Fair Value	778
Securities available for sale, Fair Value, Total	1,315	1,019
Securities available for sale, Less than 12 months, Unrealized Losses	18	71
Securities available for sale, 12 months or more, Unrealized Losses	25
Securities available for sale, Unrealized Losses, Total	43	71
Other debt securities, Other
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	15	34
Securities available for sale, 12 months or more, Fair Value	34	13
Securities available for sale, Fair Value, Total	49	47
Securities available for sale, Less than 12 months, Unrealized Losses	1	3
Securities available for sale, 12 months or more, Unrealized Losses	4	1
Securities available for sale, Unrealized Losses, Total	5	4
Equity securities
Securities available for sale
Securities available for sale, Less than 12 months, Fair Value	5
Securities available for sale, Fair Value, Total	$ 5