Fair Value Election and Measurement Level 3 Significant Unobservable Input Assumptions (Details) (USD $) In Millions, unless otherwise specified																																																													12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2012 Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Collateralized Debt Obligations [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Collateralized Debt Obligations [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Asset-backed Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Asset-backed Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 US States and Political Subdivisions Debt Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 US States and Political Subdivisions Debt Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Corporate And Other Debt Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Corporate And Other Debt Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Residential Mortgage, Loans Held For Sale [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Residential Mortgage, Loans Held For Sale [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Residential Mortgage, Loans Held For Sale [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Residential Mortgage, Loans Held For Sale [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Available-for-sale Securities [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Available-for-sale Securities [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Available-for-sale Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Available-for-sale Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Available-for-sale Securities [Member] Mortgage-backed Securities, Issued by Private Enterprises [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Available-for-sale Securities [Member] Mortgage-backed Securities, Issued by Private Enterprises [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Available-for-sale Securities [Member] Mortgage-backed Securities, Issued by Private Enterprises [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Available-for-sale Securities [Member] Mortgage-backed Securities, Issued by Private Enterprises [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Available-for-sale Securities [Member] Collateralized Debt Obligations [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Available-for-sale Securities [Member] Collateralized Debt Obligations [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Available-for-sale Securities [Member] Asset-backed Securities [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Available-for-sale Securities [Member] Asset-backed Securities [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Available-for-sale Securities [Member] Asset-backed Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Available-for-sale Securities [Member] Asset-backed Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Available-for-sale Securities [Member] US States and Political Subdivisions Debt Securities [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Available-for-sale Securities [Member] US States and Political Subdivisions Debt Securities [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Available-for-sale Securities [Member] US States and Political Subdivisions Debt Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Available-for-sale Securities [Member] US States and Political Subdivisions Debt Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Available-for-sale Securities [Member] Corporate And Other Debt Securities [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Available-for-sale Securities [Member] Corporate And Other Debt Securities [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Available-for-sale Securities [Member] Corporate And Other Debt Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2011 Available-for-sale Securities [Member] Corporate And Other Debt Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Market Approach Valuation Technique [Member] Mortgage-backed Securities, Issued by Private Enterprises [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Market Approach Valuation Technique [Member] Asset-backed Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Market Approach Valuation Technique [Member] Loans Held For Investment [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Market Approach Valuation Technique [Member] Other Assets And Liabilities, Net [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]		Dec. 31, 2012 Market Approach Valuation Technique [Member] Available-for-sale Securities [Member] Mortgage-backed Securities, Issued by Private Enterprises [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Market Approach Valuation Technique [Member] Available-for-sale Securities [Member] Asset-backed Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Market Approach Valuation Technique [Member] Available-for-sale Securities [Member] US States and Political Subdivisions Debt Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Cost Approach Valuation Technique [Member] Available-for-sale Securities [Member] Corporate And Other Debt Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Cost Approach Valuation Technique [Member] Available-for-sale Securities [Member] Equity Securities, Other [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Income Approach Valuation Technique [Member] Collateralized Debt Obligations [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Income Approach Valuation Technique [Member] Residential Mortgage, Loans Held For Sale [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Income Approach Valuation Technique [Member] Loans Held For Investment [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Income Approach Valuation Technique [Member] Mortgage Servicing Rights [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Income Approach Valuation Technique [Member] Other Assets And Liabilities, Net [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]		Dec. 31, 2012 Income Approach Valuation Technique [Member] Other Liabilities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]		Dec. 31, 2012 Lower Limit Market Approach Valuation Technique [Member] Collateralized Debt Obligations [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Lower Limit Market Approach Valuation Technique [Member] Asset-backed Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Lower Limit Market Approach Valuation Technique [Member] Other Assets And Liabilities, Net [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Lower Limit Market Approach Valuation Technique [Member] Available-for-sale Securities [Member] US States and Political Subdivisions Debt Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Lower Limit Income Approach Valuation Technique [Member] Residential Mortgage, Loans Held For Sale [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Lower Limit Income Approach Valuation Technique [Member] Loans Held For Investment [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Lower Limit Income Approach Valuation Technique [Member] Mortgage Servicing Rights [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Lower Limit Income Approach Valuation Technique [Member] Other Assets And Liabilities, Net [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Upper Limit Market Approach Valuation Technique [Member] Collateralized Debt Obligations [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Upper Limit Market Approach Valuation Technique [Member] Asset-backed Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Upper Limit Market Approach Valuation Technique [Member] Other Assets And Liabilities, Net [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Upper Limit Market Approach Valuation Technique [Member] Available-for-sale Securities [Member] US States and Political Subdivisions Debt Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Upper Limit Income Approach Valuation Technique [Member] Residential Mortgage, Loans Held For Sale [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Upper Limit Income Approach Valuation Technique [Member] Loans Held For Investment [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Upper Limit Income Approach Valuation Technique [Member] Mortgage Servicing Rights [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Upper Limit Income Approach Valuation Technique [Member] Other Assets And Liabilities, Net [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Weighted Average [Member] Market Approach Valuation Technique [Member] Collateralized Debt Obligations [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Weighted Average [Member] Market Approach Valuation Technique [Member] Asset-backed Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Weighted Average [Member] Market Approach Valuation Technique [Member] Other Assets And Liabilities, Net [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Weighted Average [Member] Market Approach Valuation Technique [Member] Available-for-sale Securities [Member] US States and Political Subdivisions Debt Securities [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Weighted Average [Member] Income Approach Valuation Technique [Member] Residential Mortgage, Loans Held For Sale [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Weighted Average [Member] Income Approach Valuation Technique [Member] Loans Held For Investment [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Weighted Average [Member] Income Approach Valuation Technique [Member] Mortgage Servicing Rights [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]	Dec. 31, 2012 Weighted Average [Member] Income Approach Valuation Technique [Member] Other Assets And Liabilities, Net [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Measurements, Recurring [Member]
level 3 fair value assumptions [Line Items]
Trading Account Assets, Fair Value Disclosure	$ 6,049		$ 6,279		$ 6,049	$ 6,279	$ 58	$ 49	$ 52	$ 43	$ 5	$ 5	$ 0	$ 0	$ 1	$ 1																											$ 1	$ 5									$ 52
Investments, Fair Value Disclosure																					21,953	28,117	914	1,041	209	221	209	221	50	0	216	464	21	16	320	454	46	58	46	51	5	5						209	21	46	5	633
Loans Held-for-sale, Fair Value Disclosure	3,243	[1]	2,141	[1]	3,243	2,141	8	1									2,924	1,826	8	1																																		8
Loans, Held for Investment, Fair Value Disclosure					379	433	379	433																																					10										369
Intangible Assets, Fair Value Disclosure					899	921	899	921																																																899
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset and Liabilities																																														132	[2]										(24)	[2]	(7)	[2]
Fair Value Inputs, Discount Rate, Variable Spread																																																													33								45								40
Fair Value Inputs, Expected Collateral Losses																																																													34.00%								45.00%								39.00%
Fair Value Inputs, Indicative Pricing																																																														$ 45		$ 72						$ 45		$ 115						$ 45		$ 92
Fair Value Inputs, Option Adjusted Spread																																																																	0.00%	0.00%							0.00%	6.22%							0.00%	2.51%
Fair Value Inputs, Conditional Prepayment Rate																																																																	0.00%	5.00%	6.00%						30.00%	30.00%	31.00%						15.00%	15.00%	16.00%
Fair Value Inputs, Probability of Default																																																																	0.00%	0.00%							20.00%	20.00%							3.50%	3.50%
Fair Value Inputs, Discount Rate																																																																			9.00%								28.00%								11.00%
Fair Value Inputs, Pull Through Rate																																																															9.00%								98.00%								71.00%
Fair Value Inputs, Msr Value																																																															0.06%								2.44%								1.04%
fair value inputs, loan production volume																																																																				0.00%								150.00%								92.00%

[1] 1 Includes loans held for sale, at fair value, of consolidated VIEs319 315

[2] Input assumptions relate to the Company's IRLCs and the contingent consideration obligations related to acquisitions. Refer to Note 17, "Reinsurance Arrangements and Guarantees," for additional information.