Fair Value (Schedule Of Fair Value Measurements On A Recurring Basis) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	$ 637,000,000		$ 707,000,000
Reduction in Assets From Netting and the Result of Cash Collateral Deposited with Derivative Counterparties	1,410,000,000
Reduction in Liabilities From Netting and the Result of Cash Collateral Received From Derivative Counterparties	479,000,000
Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	6,980,000,000
Liabilities, Fair Value Disclosure	115,000,000
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	109,682,000,000		99,832,000,000
Derivative Assets	4,556,000,000		6,366,000,000
Other Assets, Fair Value Disclosure	68,000,000		110,000,000
Assets, Fair Value Disclosure	114,943,000,000		107,015,000,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	5,367,000,000		6,690,000,000
Other Liabilities, Fair Value Disclosure	66,000,000		130,000,000
Liabilities, Fair Value Disclosure	5,433,000,000		6,820,000,000
Fair Value, Measurements, Recurring [Member] | US Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	20,000,000		20,000,000
Fair Value, Measurements, Recurring [Member] | Non-US Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	391,000,000		498,000,000
Fair Value, Measurements, Recurring [Member] | US Treasury and Federal Agencies, Direct Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	841,000,000		2,836,000,000
Fair Value, Measurements, Recurring [Member] | US Treasury and Federal Agencies, Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	32,212,000,000		30,021,000,000
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	32,483,000,000		31,901,000,000
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities, Student Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	16,421,000,000		16,545,000,000
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities, Credit Cards [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	9,986,000,000		10,487,000,000
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities, Sub-prime [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	1,399,000,000		1,404,000,000
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities, Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	4,677,000,000		3,465,000,000
Fair Value, Measurements, Recurring [Member] | Non U S Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	25,128,000,000		19,674,000,000
Fair Value, Measurements, Recurring [Member] | Non-US Debt Securities, Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	11,405,000,000		10,875,000,000
Fair Value, Measurements, Recurring [Member] | Non-US Debt Securities, Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	6,218,000,000		4,303,000,000
Fair Value, Measurements, Recurring [Member] | Non-US Debt Securities, Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	3,199,000,000		1,671,000,000
Fair Value, Measurements, Recurring [Member] | Non-US Debt Securities, Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	4,306,000,000		2,825,000,000
Fair Value, Measurements, Recurring [Member] | State And Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	7,551,000,000		7,047,000,000
Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	4,954,000,000		3,980,000,000
Fair Value, Measurements, Recurring [Member] | Other U.S. Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	226,000,000		189,000,000
Available-for-sale Securities, Fair Value Disclosure	5,298,000,000		3,615,000,000
Fair Value, Measurements, Recurring [Member] | U.S. Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	1,092,000,000		640,000,000
Fair Value, Measurements, Recurring [Member] | Non-US Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	123,000,000		118,000,000
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	3,000,000		1,728,000,000
Derivative Assets	0		0
Other Assets, Fair Value Disclosure	66,000,000		110,000,000
Assets, Fair Value Disclosure	551,000,000		2,407,000,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure
Other Liabilities, Fair Value Disclosure	66,000,000		110,000,000
Liabilities, Fair Value Disclosure	66,000,000		110,000,000
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets			0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | US Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	20,000,000		20,000,000
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Non-US Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	391,000,000		498,000,000
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | US Treasury and Federal Agencies, Direct Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	3,000,000		1,727,000,000
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | US Treasury and Federal Agencies, Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Asset-backed Securities, Student Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Asset-backed Securities, Credit Cards [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Asset-backed Securities, Sub-prime [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Asset-backed Securities, Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Non U S Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Non-US Debt Securities, Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Non-US Debt Securities, Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Non-US Debt Securities, Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Non-US Debt Securities, Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | State And Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Other U.S. Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	71,000,000		51,000,000
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | U.S. Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Quoted Market Prices In Active Markets (Level 1) [Member] | Non-US Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		1,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	102,812,000,000		89,591,000,000
Derivative Assets	9,488,000,000		13,841,000,000
Other Assets, Fair Value Disclosure	2,000,000		0
Assets, Fair Value Disclosure	112,457,000,000		103,570,000,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	9,323,000,000		14,162,000,000
Other Liabilities, Fair Value Disclosure	0		0
Liabilities, Fair Value Disclosure	9,323,000,000		14,162,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	9,265,000,000		12,045,000,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	8,978,000,000		12,191,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	223,000,000		1,795,000,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	345,000,000		1,970,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets			1,000,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0		1,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | US Treasury and Federal Agencies, Direct Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	838,000,000		1,109,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | US Treasury and Federal Agencies, Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	31,387,000,000		28,832,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	27,834,000,000		28,152,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Asset-backed Securities, Student Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	15,833,000,000		15,685,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Asset-backed Securities, Credit Cards [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	9,919,000,000		10,396,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Asset-backed Securities, Sub-prime [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	1,399,000,000		1,404,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Asset-backed Securities, Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	683,000,000		667,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Non U S Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	23,909,000,000		16,378,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Non-US Debt Securities, Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	10,850,000,000		9,418,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Non-US Debt Securities, Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	5,694,000,000		2,535,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Non-US Debt Securities, Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	3,199,000,000		1,671,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Non-US Debt Securities, Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	4,166,000,000		2,754,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | State And Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	7,503,000,000		6,997,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	4,837,000,000		3,753,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Other U.S. Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	155,000,000		138,000,000
Available-for-sale Securities, Fair Value Disclosure	5,289,000,000		3,613,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | U.S. Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	1,092,000,000		640,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Observable Market Inputs (Level 2) [Member] | Non-US Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	123,000,000		117,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	6,867,000,000		8,513,000,000
Derivative Assets	113,000,000		178,000,000
Other Assets, Fair Value Disclosure	0		0
Assets, Fair Value Disclosure	6,980,000,000		8,691,000,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	115,000,000		181,000,000
Other Liabilities, Fair Value Disclosure	0		20,000,000
Liabilities, Fair Value Disclosure	115,000,000		201,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	113,000,000		168,000,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	106,000,000		161,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	0		10,000,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	0		11,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets			0
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	9,000,000		9,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | US Treasury and Federal Agencies, Mortgage-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	825,000,000		1,189,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Asset-backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	4,649,000,000		3,749,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Asset-backed Securities, Student Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	588,000,000		860,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Asset-backed Securities, Credit Cards [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	67,000,000		91,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Asset-backed Securities, Sub-prime [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Asset-backed Securities, Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	3,994,000,000		2,798,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Non U S Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	1,219,000,000		3,296,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Non-US Debt Securities, Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	555,000,000		1,457,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Non-US Debt Securities, Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	524,000,000		1,768,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Non-US Debt Securities, Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Non-US Debt Securities, Other [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	140,000,000		71,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | State And Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	48,000,000		50,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	117,000,000		227,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Other U.S. Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	9,000,000		2,000,000
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | U.S. Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Pricing Methods With Significant Unobservable Market Inputs (Level 3) [Member] | Non-US Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Netting and Collateral [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets	(5,045,000,000)	[1]	(7,653,000,000)	[2]
Other Assets, Fair Value Disclosure	0	[1]	0	[2]
Assets, Fair Value Disclosure	(5,045,000,000)	[1]	(7,653,000,000)	[2]
Derivative Financial Instruments, Liabilities, Fair Value Disclosure	(4,071,000,000)	[1]	(7,653,000,000)	[2]
Other Liabilities, Fair Value Disclosure	0	[1]	0	[2]
Liabilities, Fair Value Disclosure	$ (4,071,000,000)	[1]	$ (7,653,000,000)	[2]

[1] Represents counterparty netting against level-2 financial assets and liabilities, where a legally enforceable master netting agreement exists between State Street and the counterparty. Netting also reflects asset and liability reductions of $1.41 billion and $479 million, respectively, for cash collateral received from and deposited with derivative counterparties. This netting cannot be disaggregated by type of derivative instrument.

[2] Represents counterparty netting against level-2 financial assets and liabilities, where a legally enforceable master netting agreement exists between State Street and the counterparty. This netting cannot be disaggregated by type of derivative instrument.