Variable Interest Entities - Variable Interests Held by Us and Our Maximum Exposure to Loss Rising From Our Involvements in Those VIEs (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Variable Interest Entity [Line Items]
Variable Interest Held Classified as Assets	$ 2,894	$ 2,689
Variable Interests Held Classified as Liabilities	12	55
Total Assets in Unconsolidated VIEs	16,577	23,234
Maximum Exposure to Loss	8,244	8,448
Asset-backed commercial paper conduits [Member]
Variable Interest Entity [Line Items]
Variable Interest Held Classified as Assets	59	417
Variable Interests Held Classified as Liabilities	0	0
Total Assets in Unconsolidated VIEs	10,673	17,044
Maximum Exposure to Loss	2,354	2,560
Structured note vehicles [Member]
Variable Interest Entity [Line Items]
Variable Interest Held Classified as Assets	2,830	2,272
Variable Interests Held Classified as Liabilities	8	55
Total Assets in Unconsolidated VIEs	5,899	6,190
Maximum Exposure to Loss	5,885	5,888
Low income housing partnerships [Member]
Variable Interest Entity [Line Items]
Variable Interest Held Classified as Assets	5
Variable Interests Held Classified as Liabilities	4
Total Assets in Unconsolidated VIEs	5
Maximum Exposure to Loss	$ 5