Fair Value (Schedule of Fair Value Measurements on a Recurring Basis) (Details) (USD $)	9 Months Ended		12 Months Ended
	Sep. 30, 2013		Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	$ 916,000,000		$ 637,000,000
Reduction in assets from netting and the result of cash collateral deposited with derivative counterparties	2,300,000,000		1,450,000,000
Reduction in liabilities from netting and the result of cash collateral received from derivative counterparties	468,000,000		478,000,000
Pricing Methods with Significant Unobservable Market Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value disclosure	7,380,000,000		6,980,000,000
Liabilities, fair value disclosure	64,000,000		115,000,000
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	916,000,000		637,000,000
Available-for-sale securities	99,982,000,000		109,682,000,000
Derivative assets	4,320,000,000		4,556,000,000
Other assets	101,000,000		68,000,000
Assets, fair value disclosure	105,319,000,000		114,943,000,000
Derivative instruments, liabilities	6,307,000,000		5,367,000,000
Other liabilities	101,000,000		66,000,000
Liabilities, fair value disclosure	6,408,000,000		5,433,000,000
Recurring | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	4,306,000,000		4,397,000,000
Derivative instruments, liabilities	6,050,000,000		5,032,000,000
Recurring | Interest-rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	13,000,000		159,000,000
Derivative instruments, liabilities	248,000,000		326,000,000
Recurring | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1,000,000
Derivative instruments, liabilities	9,000,000		9,000,000
Recurring | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	20,000,000		20,000,000
Recurring | Non-U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	392,000,000		391,000,000
Recurring | US Treasury and federal agencies, direct obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	738,000,000		841,000,000
Recurring | US Treasury and federal agencies, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	24,575,000,000		32,212,000,000
Recurring | Total asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	29,664,000,000		32,483,000,000
Recurring | Asset-backed securities, student loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	14,871,000,000		16,421,000,000
Recurring | Asset-backed securities, credit cards
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	8,626,000,000		9,986,000,000
Recurring | Asset-backed securities, sub-prime
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	1,266,000,000		1,399,000,000
Recurring | Asset-backed securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	4,901,000,000		4,677,000,000
Recurring | Total non-U.S. debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	24,609,000,000		25,128,000,000
Recurring | Non-U.S. debt securities, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	11,001,000,000		11,405,000,000
Recurring | Non-U.S. debt securities, asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	5,467,000,000		6,218,000,000
Recurring | Non-US debt securities, government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	3,541,000,000		3,199,000,000
Recurring | Non-U.S. debt securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	4,600,000,000		4,306,000,000
Recurring | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	9,298,000,000		7,551,000,000
Recurring | Collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	5,158,000,000		4,954,000,000
Recurring | Other U.S.debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	504,000,000		226,000,000
Available-for-sale securities	5,045,000,000		5,298,000,000
Recurring | U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	39,000,000		31,000,000
Recurring | Non-U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	2,000,000		1,000,000
Recurring | U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	680,000,000		1,062,000,000
Recurring | Non-U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	174,000,000		121,000,000
Recurring | Quoted Market Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	478,000,000		482,000,000
Available-for-sale securities	0		3,000,000
Derivative assets	0		0
Other assets	101,000,000		66,000,000
Assets, fair value disclosure	579,000,000		551,000,000
Derivative instruments, liabilities
Other liabilities	101,000,000		66,000,000
Liabilities, fair value disclosure	101,000,000		66,000,000
Recurring | Quoted Market Prices in Active Markets (Level 1) | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Interest-rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0
Recurring | Quoted Market Prices in Active Markets (Level 1) | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	20,000,000		20,000,000
Recurring | Quoted Market Prices in Active Markets (Level 1) | Non-U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	392,000,000		391,000,000
Recurring | Quoted Market Prices in Active Markets (Level 1) | US Treasury and federal agencies, direct obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		3,000,000
Recurring | Quoted Market Prices in Active Markets (Level 1) | US Treasury and federal agencies, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Total asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Asset-backed securities, student loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Asset-backed securities, credit cards
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Asset-backed securities, sub-prime
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Asset-backed securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Total non-U.S. debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Non-U.S. debt securities, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Non-U.S. debt securities, asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Non-US debt securities, government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Non-U.S. debt securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Other U.S.debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	66,000,000		71,000,000
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Non-U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Quoted Market Prices in Active Markets (Level 1) | Non-U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	438,000,000		155,000,000
Available-for-sale securities	92,679,000,000		102,812,000,000
Derivative assets	10,348,000,000		9,488,000,000
Other assets	0		2,000,000
Assets, fair value disclosure	103,465,000,000		112,457,000,000
Derivative instruments, liabilities	10,513,000,000		9,323,000,000
Other liabilities	0		0
Liabilities, fair value disclosure	10,513,000,000		9,323,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	10,289,000,000		9,265,000,000
Derivative instruments, liabilities	10,206,000,000		8,978,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Interest-rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	58,000,000		223,000,000
Derivative instruments, liabilities	307,000,000		345,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1,000,000
Derivative instruments, liabilities	0		0
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | US Treasury and federal agencies, direct obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	738,000,000		838,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | US Treasury and federal agencies, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	23,834,000,000		31,387,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Total asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	24,922,000,000		27,834,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Asset-backed securities, student loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	14,503,000,000		15,833,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Asset-backed securities, credit cards
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	8,602,000,000		9,919,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Asset-backed securities, sub-prime
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	1,266,000,000		1,399,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Asset-backed securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	551,000,000		683,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Total non-U.S. debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	23,029,000,000		23,909,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Non-U.S. debt securities, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	10,661,000,000		10,850,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Non-U.S. debt securities, asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	4,668,000,000		5,694,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Non-US debt securities, government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	3,541,000,000		3,199,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Non-U.S. debt securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	4,159,000,000		4,166,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	9,254,000,000		7,503,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	4,971,000,000		4,837,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Other U.S.debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading account assets	438,000,000		155,000,000
Available-for-sale securities	5,036,000,000		5,289,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	39,000,000		31,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Non-U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	2,000,000		1,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	680,000,000		1,062,000,000
Recurring | Pricing Methods with Significant Observable Market Inputs (Level 2) | Non-U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	174,000,000		121,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	7,303,000,000		6,867,000,000
Derivative assets	77,000,000		113,000,000
Other assets	0		0
Assets, fair value disclosure	7,380,000,000		6,980,000,000
Derivative instruments, liabilities	64,000,000		115,000,000
Other liabilities	0		0
Liabilities, fair value disclosure	64,000,000		115,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	77,000,000		113,000,000
Derivative instruments, liabilities	55,000,000		106,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Interest-rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0		0
Derivative instruments, liabilities	0		0
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0
Derivative instruments, liabilities	9,000,000		9,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | US Treasury and federal agencies, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	741,000,000		825,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Total asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	4,742,000,000		4,649,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Asset-backed securities, student loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	368,000,000		588,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Asset-backed securities, credit cards
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	24,000,000		67,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Asset-backed securities, sub-prime
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Asset-backed securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	4,350,000,000		3,994,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Total non-U.S. debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	1,580,000,000		1,219,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-U.S. debt securities, mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	340,000,000		555,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-U.S. debt securities, asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	799,000,000		524,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-US debt securities, government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-U.S. debt securities, other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	441,000,000		140,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	44,000,000		48,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	187,000,000		117,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Other U.S.debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	9,000,000		9,000,000
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-U.S. equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Pricing Methods with Significant Unobservable Market Inputs (Level 3) | Non-U.S. money-market mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities	0		0
Recurring | Impact of Netting
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	(6,105,000,000)	[1]	(5,045,000,000)
Other assets	0	[1]	0	[2]
Assets, fair value disclosure	(6,105,000,000)	[1]	(5,045,000,000)	[2]
Derivative instruments, liabilities	(4,270,000,000)	[1]	(4,071,000,000)
Other liabilities	0	[1]	0	[2]
Liabilities, fair value disclosure	(4,270,000,000)	[1]	(4,071,000,000)	[2]
Recurring | Impact of Netting | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	(6,060,000,000)	[1]	(4,981,000,000)	[2]
Derivative instruments, liabilities	(4,211,000,000)	[1]	(4,052,000,000)	[2]
Recurring | Impact of Netting | Interest-rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	(45,000,000)	[1]	(64,000,000)	[2]
Derivative instruments, liabilities	(59,000,000)	[1]	(19,000,000)	[2]
Recurring | Impact of Netting | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	[1]
Derivative instruments, liabilities	$ 0	[1]	$ 0	[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 $2.30 billion and $468 million, respectively, for cash collateral received from and provided to derivative counterparties.

[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. Netting also reflects asset and liability reductions of $1.45 billion and $478 million, respectively, for cash collateral received from and provided to derivative counterparties.