Investment Securities (Investment) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Investment [Line Items]
Net pre-tax gains (loss) on trading securities	$ 20	$ 22	$ (7)
Marketable securities OTTI amounts	192	467	460
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities	140	387	253
Marketable securities OTTI recorded in AOCI	52	80	207
Marketable Securities, Realized Loss, Other than Temporary Impairments, Amount	140	387	253
Incremental Charges On Previously Impaired Investment Securities	40	230	38
Other Than Temporary Impairment Related To Equity Securities	38	81	35
Other Than Temporary First Time Impairments Of Investment Securities Recognized In Earnings	27	58	164
Other Than Temporary Impairment Related To Securities Subsequently Sold	219	62	41
Proceeds from Sale of Available-for-sale Securities	12,792	15,606	16,221
Cumulative Impairments Recognized In Earnings	558	332	172
Domestic Corporate Debt Securities [Member]
Investment [Line Items]
Investment securities gross unrealized gains	4,201	3,432
Investment securities gross unrealized loss	(302)	(410)
Domestic Corporate Debt Securities [Member] \| Amortized Cost [Member]
Investment [Line Items]
Investment securities amortized cost	20,233	20,748
Domestic Corporate Debt Securities [Member] \| Estimated Fair Value [Member]
Investment [Line Items]
Investment securities estimated fair value	24,132	23,770
US States and Political Subdivisions Debt Securities [Member]
Investment [Line Items]
Investment securities gross unrealized gains	575	350
Investment securities gross unrealized loss	(113)	(143)
US States and Political Subdivisions Debt Securities [Member] \| Amortized Cost [Member]
Investment [Line Items]
Investment securities amortized cost	4,084	3,027
US States and Political Subdivisions Debt Securities [Member] \| Estimated Fair Value [Member]
Investment [Line Items]
Investment securities estimated fair value	4,546	3,234
Residential Mortgage Backed Securities [Member]
Investment [Line Items]
Investment securities gross unrealized gains	183	184
Investment securities gross unrealized loss	(119)	(286)
Residential Subprime Credit	471	515
Residential Subprime Credit Exposure	219	277
Residential Mortgage Backed Securities [Member] \| Amortized Cost [Member]
Investment [Line Items]
Investment securities amortized cost	2,198	2,711
Residential Mortgage Backed Securities [Member] \| Estimated Fair Value [Member]
Investment [Line Items]
Investment securities estimated fair value	2,262	2,609
Commercial Mortgage Backed Securities [Member]
Investment [Line Items]
Investment securities gross unrealized gains	259	162
Investment securities gross unrealized loss	(95)	(247)
Commercial Mortgage Backed Securities [Member] \| Amortized Cost [Member]
Investment [Line Items]
Investment securities amortized cost	2,930	2,913
Commercial Mortgage Backed Securities [Member] \| Estimated Fair Value [Member]
Investment [Line Items]
Investment securities estimated fair value	3,094	2,828
Asset-backed Securities [Member]
Investment [Line Items]
Investment securities gross unrealized gains	31	32
Investment securities gross unrealized loss	(77)	(164)
Asset-backed Securities [Member] \| Amortized Cost [Member]
Investment [Line Items]
Investment securities amortized cost	5,784	5,102
Asset-backed Securities [Member] \| Estimated Fair Value [Member]
Investment [Line Items]
Investment securities estimated fair value	5,738	4,970
Foreign Corporate Debt Securities [Member]
Investment [Line Items]
Investment securities gross unrealized gains	150	126
Investment securities gross unrealized loss	(126)	(207)
Foreign Corporate Debt Securities [Member] \| Amortized Cost [Member]
Investment [Line Items]
Investment securities amortized cost	2,391	2,414
Foreign Corporate Debt Securities [Member] \| Estimated Fair Value [Member]
Investment [Line Items]
Investment securities estimated fair value	2,415	2,333
Foreign Government Debt Securities [Member]
Investment [Line Items]
Investment securities gross unrealized gains	149	129
Investment securities gross unrealized loss	(3)	(86)
Foreign Government Debt Securities [Member] \| Amortized Cost [Member]
Investment [Line Items]
Investment securities amortized cost	1,617	2,488
Foreign Government Debt Securities [Member] \| Estimated Fair Value [Member]
Investment [Line Items]
Investment securities estimated fair value	1,763	2,531
US Treasury and Government [Member]
Investment [Line Items]
Investment securities gross unrealized gains	103	84
Investment securities gross unrealized loss	0	0
US Treasury and Government [Member] \| Amortized Cost [Member]
Investment [Line Items]
Investment securities amortized cost	3,462	3,974
US Treasury and Government [Member] \| Estimated Fair Value [Member]
Investment [Line Items]
Investment securities estimated fair value	3,565	4,058
Retained Interest [Member]
Investment [Line Items]
Investment securities gross unrealized gains	7	10
Investment securities gross unrealized loss	0	0
Retained Interest [Member] \| Amortized Cost [Member]
Investment [Line Items]
Investment securities amortized cost	76	25
Retained Interest [Member] \| Estimated Fair Value [Member]
Investment [Line Items]
Investment securities estimated fair value	83	35
Available-for-sale Securities [Member]
Investment [Line Items]
Investment securities gross unrealized gains	86	75
Investment securities gross unrealized loss	(3)	(38)
Available-for-sale Securities [Member] \| Amortized Cost [Member]
Investment [Line Items]
Investment securities amortized cost	513	713
Available-for-sale Securities [Member] \| Estimated Fair Value [Member]
Investment [Line Items]
Investment securities estimated fair value	596	750
Trading Securities [Member]
Investment [Line Items]
Investment securities gross unrealized gains	0	0
Investment securities gross unrealized loss	0	0
Trading Securities [Member] \| Amortized Cost [Member]
Investment [Line Items]
Investment securities amortized cost	245	241
Trading Securities [Member] \| Estimated Fair Value [Member]
Investment [Line Items]
Investment securities estimated fair value	245	241
Total [Member]
Investment [Line Items]
Investment securities gross unrealized gains	5,744	4,584
Investment securities gross unrealized loss	(838)	(1,581)
Total [Member] \| Amortized Cost [Member]
Investment [Line Items]
Investment securities amortized cost	43,533	44,356
Total [Member] \| Estimated Fair Value [Member]
Investment [Line Items]
Investment securities estimated fair value	$ 48,439	$ 47,359

The amount of cumulative impairments recognized in earnings.

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Amounts included in accumulated other comprehensive income that are related to marketable securities other than temporary impairment impairments realized gain or loss.

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Impairment losses that were other than temporary and were recorded in through earnings.

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Impairment losses that were other than temporary and were recorded in through earnings related to equity securities.

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Assets within the RMBS portfolio that relate to residential subprime credit.

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The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.

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