Fair Value Measurements - Assets and Liabilities Recorded at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions		Dec. 31, 2016		Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Netting, Assets	[1],[2]	$ (51,111)		$ (55,510)
Netting Liabilities	[1],[2]	(51,111)		(55,510)
Trading assets		16,850		17,085
Trading liabilities		4,908		7,455
Obligations of U.S. states and political subdivision [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading assets		0		559
Precious metals [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading assets		1,772		780
Trading liabilities		62		650
Other securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading assets		15		18
Derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading liabilities		3,786		6,406
Derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading assets		4,411		5,150
Estimate of fair value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		112,104		114,065
Netting, Assets	[3]	(56,256)		(60,452)
Net Balance, Assets		55,848		53,613
Gross Balance, Liabilities		81,176		83,148
Netting Liabilities	[3]	(54,937)		(57,040)
Net Balance, Liabilities		26,239		26,108
Estimate of fair value [Member] | Trading liabilities excluding derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities		1,122		1,049
Net Balance, Liabilities		1,122		1,049
Estimate of fair value [Member] | Derivative Financial Instruments, Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	59,472		64,033
Netting Liabilities	[3],[4]	(54,937)		(57,040)
Net Balance, Liabilities	[4]	4,535		6,993
Estimate of fair value [Member] | Derivative Financial Instruments, Liabilities [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	32,652		35,461
Netting Liabilities	[3],[4]	0		0
Net Balance, Liabilities	[4]	32,652		35,461
Estimate of fair value [Member] | Derivative Financial Instruments, Liabilities [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	22,682		22,436
Netting Liabilities	[3],[4]	0		0
Net Balance, Liabilities	[4]	22,682		22,436
Estimate of fair value [Member] | Derivative Financial Instruments, Liabilities [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	1,875		1,762
Netting Liabilities	[3],[4]	0		0
Net Balance, Liabilities	[4]	1,875		1,762
Estimate of fair value [Member] | Derivative Financial Instruments, Liabilities [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	880		591
Netting Liabilities	[3],[4]	0		0
Net Balance, Liabilities	[4]	880		591
Estimate of fair value [Member] | Derivative Financial Instruments, Liabilities [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	1,369		3,783
Netting Liabilities	[3],[4]	0		0
Net Balance, Liabilities	[4]	1,369		3,783
Estimate of fair value [Member] | Derivative Financial Instruments, Liabilities [Member] | Other Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4],[5]	14
Netting Liabilities	[3],[4],[5]	0
Net Balance, Liabilities	[4],[5]	14
Estimate of fair value [Member] | Derivative Financial Instruments, Liabilities [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	0		0
Netting Liabilities	[3],[4]	(54,937)		(57,040)
Net Balance, Liabilities	[4]	(54,937)		(57,040)
Estimate of fair value [Member] | Securities Purchased under Agreements to Resell [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[6]	770
Net Balance, Assets	[6]	770
Estimate of fair value [Member] | Trading Securities, excluding derivatives [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		3,806		3,255
Net Balance, Assets		3,806		3,255
Estimate of fair value [Member] | Trading Securities, excluding derivatives [Member] | Obligations of U.S. states and political subdivision [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				559
Net Balance, Assets				559
Estimate of fair value [Member] | Trading Securities, excluding derivatives [Member] | Collateralized debt obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		184		221
Net Balance, Assets		184		221
Estimate of fair value [Member] | Trading Securities, excluding derivatives [Member] | Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		96		114
Net Balance, Assets		96		114
Estimate of fair value [Member] | Trading Securities, excluding derivatives [Member] | Student Loan Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		85		89
Net Balance, Assets		85		89
Estimate of fair value [Member] | Trading Securities, excluding derivatives [Member] | Corporate and other domestic debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		2,884		2,870
Net Balance, Assets		2,884		2,870
Estimate of fair value [Member] | Trading Securities, excluding derivatives [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		3,597
Net Balance, Assets		3,597
Estimate of fair value [Member] | Trading Securities, excluding derivatives [Member] | Corporate debt securities issued by foreign entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				55
Net Balance, Assets				55
Estimate of fair value [Member] | Trading Securities, excluding derivatives [Member] | Government debt securities issued by foreign entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				3,974
Net Balance, Assets				3,974
Estimate of fair value [Member] | Trading Securities, excluding derivatives [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		15		18
Net Balance, Assets		15		18
Estimate of fair value [Member] | Trading Securities, excluding derivatives [Member] | Precious metals [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		1,772		780
Net Balance, Assets		1,772		780
Estimate of fair value [Member] | Derivative financial assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	61,260		66,066
Netting, Assets	[3],[4]	(56,256)		(60,452)
Net Balance, Assets	[4]	5,004		5,614
Estimate of fair value [Member] | Derivative financial assets [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	32,200		35,269
Netting, Assets	[3],[4]	0		0
Net Balance, Assets	[4]	32,200		35,269
Estimate of fair value [Member] | Derivative financial assets [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	24,056		24,177
Netting, Assets	[3],[4]	0		0
Net Balance, Assets	[4]	24,056		24,177
Estimate of fair value [Member] | Derivative financial assets [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	2,330		1,806
Netting, Assets	[3],[4]	0		0
Net Balance, Assets	[4]	2,330		1,806
Estimate of fair value [Member] | Derivative financial assets [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	1,119		929
Netting, Assets	[3],[4]	0		0
Net Balance, Assets	[4]	1,119		929
Estimate of fair value [Member] | Derivative financial assets [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	1,550		3,885
Netting, Assets	[3],[4]	0		0
Net Balance, Assets	[4]	1,550		3,885
Estimate of fair value [Member] | Derivative financial assets [Member] | Other Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4],[5]	5
Netting, Assets	[3],[4],[5]	0
Net Balance, Assets	[4],[5]	5
Estimate of fair value [Member] | Derivative financial assets [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	0		0
Netting, Assets	[3],[4]	(56,256)		(60,452)
Net Balance, Assets	[4]	(56,256)		(60,452)
Estimate of fair value [Member] | Securities available-for-sale [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		36,069		34,545
Net Balance, Assets		36,069		34,545
Estimate of fair value [Member] | Securities available-for-sale [Member] | Obligations of U.S. states and political subdivision [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				348
Net Balance, Assets				348
Estimate of fair value [Member] | Securities available-for-sale [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		521		546
Net Balance, Assets		521		546
Estimate of fair value [Member] | Securities available-for-sale [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		154		161
Net Balance, Assets		154		161
Estimate of fair value [Member] | Securities available-for-sale [Member] | Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				9
Net Balance, Assets				9
Estimate of fair value [Member] | Securities available-for-sale [Member] | Home Equity Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		61		75
Net Balance, Assets		61		75
Estimate of fair value [Member] | Securities available-for-sale [Member] | Other securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		105		89
Net Balance, Assets		105		89
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		28,846		25,076
Gross Balance, Liabilities		1,163		445
Level 1 [Member] | Trading liabilities excluding derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities		1,060		363
Level 1 [Member] | Derivative Financial Instruments, Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	103		82
Level 1 [Member] | Derivative Financial Instruments, Liabilities [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	84		28
Level 1 [Member] | Derivative Financial Instruments, Liabilities [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	6		15
Level 1 [Member] | Derivative Financial Instruments, Liabilities [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	0		0
Level 1 [Member] | Derivative Financial Instruments, Liabilities [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	13		39
Level 1 [Member] | Derivative Financial Instruments, Liabilities [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	0		0
Level 1 [Member] | Derivative Financial Instruments, Liabilities [Member] | Other Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4],[5]	0
Level 1 [Member] | Derivative Financial Instruments, Liabilities [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	0		0
Level 1 [Member] | Securities Purchased under Agreements to Resell [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[6]	0
Level 1 [Member] | Trading Securities, excluding derivatives [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		3,560		3,088
Level 1 [Member] | Trading Securities, excluding derivatives [Member] | Obligations of U.S. states and political subdivision [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				0
Level 1 [Member] | Trading Securities, excluding derivatives [Member] | Collateralized debt obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 1 [Member] | Trading Securities, excluding derivatives [Member] | Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 1 [Member] | Trading Securities, excluding derivatives [Member] | Student Loan Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 1 [Member] | Trading Securities, excluding derivatives [Member] | Corporate and other domestic debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 1 [Member] | Trading Securities, excluding derivatives [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets
Level 1 [Member] | Trading Securities, excluding derivatives [Member] | Corporate debt securities issued by foreign entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				0
Level 1 [Member] | Trading Securities, excluding derivatives [Member] | Government debt securities issued by foreign entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				0
Level 1 [Member] | Trading Securities, excluding derivatives [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 1 [Member] | Trading Securities, excluding derivatives [Member] | Precious metals [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 1 [Member] | Derivative financial assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	141		64
Level 1 [Member] | Derivative financial assets [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	36		26
Level 1 [Member] | Derivative financial assets [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	24		0
Level 1 [Member] | Derivative financial assets [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	0		0
Level 1 [Member] | Derivative financial assets [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	81		38
Level 1 [Member] | Derivative financial assets [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	0		0
Level 1 [Member] | Derivative financial assets [Member] | Other Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4],[5]	0
Level 1 [Member] | Derivative financial assets [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	0		0
Level 1 [Member] | Securities available-for-sale [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		25,145		21,924
Level 1 [Member] | Securities available-for-sale [Member] | Obligations of U.S. states and political subdivision [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				0
Level 1 [Member] | Securities available-for-sale [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 1 [Member] | Securities available-for-sale [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 1 [Member] | Securities available-for-sale [Member] | Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				0
Level 1 [Member] | Securities available-for-sale [Member] | Home Equity Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 1 [Member] | Securities available-for-sale [Member] | Other securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		79,694		85,412
Gross Balance, Liabilities		77,899		79,841
Level 2 [Member] | Trading liabilities excluding derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities		62		686
Level 2 [Member] | Derivative Financial Instruments, Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	59,161		63,702
Level 2 [Member] | Derivative Financial Instruments, Liabilities [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	32,568		35,432
Level 2 [Member] | Derivative Financial Instruments, Liabilities [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	22,658		22,405
Level 2 [Member] | Derivative Financial Instruments, Liabilities [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	1,714		1,560
Level 2 [Member] | Derivative Financial Instruments, Liabilities [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	867		552
Level 2 [Member] | Derivative Financial Instruments, Liabilities [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	1,354		3,753
Level 2 [Member] | Derivative Financial Instruments, Liabilities [Member] | Other Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4],[5]	0
Level 2 [Member] | Derivative Financial Instruments, Liabilities [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	0		0
Level 2 [Member] | Securities Purchased under Agreements to Resell [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[6]	770
Level 2 [Member] | Trading Securities, excluding derivatives [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		246		167
Level 2 [Member] | Trading Securities, excluding derivatives [Member] | Obligations of U.S. states and political subdivision [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				559
Level 2 [Member] | Trading Securities, excluding derivatives [Member] | Collateralized debt obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 2 [Member] | Trading Securities, excluding derivatives [Member] | Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		96		114
Level 2 [Member] | Trading Securities, excluding derivatives [Member] | Student Loan Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		85		89
Level 2 [Member] | Trading Securities, excluding derivatives [Member] | Corporate and other domestic debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 2 [Member] | Trading Securities, excluding derivatives [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		3,597
Level 2 [Member] | Trading Securities, excluding derivatives [Member] | Corporate debt securities issued by foreign entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				55
Level 2 [Member] | Trading Securities, excluding derivatives [Member] | Government debt securities issued by foreign entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				3,974
Level 2 [Member] | Trading Securities, excluding derivatives [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		15		18
Level 2 [Member] | Trading Securities, excluding derivatives [Member] | Precious metals [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		1,772		780
Level 2 [Member] | Derivative financial assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	60,728		65,656
Level 2 [Member] | Derivative financial assets [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	32,163		35,241
Level 2 [Member] | Derivative financial assets [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	24,014		24,161
Level 2 [Member] | Derivative financial assets [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	2,171		1,687
Level 2 [Member] | Derivative financial assets [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	1,038		891
Level 2 [Member] | Derivative financial assets [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	1,342		3,676
Level 2 [Member] | Derivative financial assets [Member] | Other Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4],[5]	0
Level 2 [Member] | Derivative financial assets [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	0		0
Level 2 [Member] | Securities available-for-sale [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		10,924		12,621
Level 2 [Member] | Securities available-for-sale [Member] | Obligations of U.S. states and political subdivision [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				348
Level 2 [Member] | Securities available-for-sale [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		521		546
Level 2 [Member] | Securities available-for-sale [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		154		161
Level 2 [Member] | Securities available-for-sale [Member] | Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				9
Level 2 [Member] | Securities available-for-sale [Member] | Home Equity Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		61		75
Level 2 [Member] | Securities available-for-sale [Member] | Other securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		89
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		3,564		3,577
Gross Balance, Liabilities		2,114		2,862
Level 3 [Member] | Collateralized debt obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		184		221
Level 3 [Member] | Corporate and other domestic debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		2,884		2,870
Level 3 [Member] | Other securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		105
Level 3 [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		1		1
Level 3 [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[7]	0		0
Level 3 [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		(2)	[7]	(83)
Level 3 [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		193		179
Level 3 [Member] | Other Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		(9)
Level 3 [Member] | Trading liabilities excluding derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities		0		0
Level 3 [Member] | Derivative Financial Instruments, Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	208		249
Level 3 [Member] | Derivative Financial Instruments, Liabilities [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	0		1
Level 3 [Member] | Derivative Financial Instruments, Liabilities [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	18		16
Level 3 [Member] | Derivative Financial Instruments, Liabilities [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	161		202
Level 3 [Member] | Derivative Financial Instruments, Liabilities [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	0		0
Level 3 [Member] | Derivative Financial Instruments, Liabilities [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	15		30
Level 3 [Member] | Derivative Financial Instruments, Liabilities [Member] | Other Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4],[5]	14
Level 3 [Member] | Derivative Financial Instruments, Liabilities [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	0		0
Level 3 [Member] | Securities Purchased under Agreements to Resell [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[6]	0
Level 3 [Member] | Trading Securities, excluding derivatives [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 3 [Member] | Trading Securities, excluding derivatives [Member] | Obligations of U.S. states and political subdivision [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				0
Level 3 [Member] | Trading Securities, excluding derivatives [Member] | Collateralized debt obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		184		221
Level 3 [Member] | Trading Securities, excluding derivatives [Member] | Residential Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 3 [Member] | Trading Securities, excluding derivatives [Member] | Student Loan Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 3 [Member] | Trading Securities, excluding derivatives [Member] | Corporate and other domestic debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		2,884		2,870
Level 3 [Member] | Trading Securities, excluding derivatives [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0
Level 3 [Member] | Trading Securities, excluding derivatives [Member] | Corporate debt securities issued by foreign entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				0
Level 3 [Member] | Trading Securities, excluding derivatives [Member] | Government debt securities issued by foreign entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				0
Level 3 [Member] | Trading Securities, excluding derivatives [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 3 [Member] | Trading Securities, excluding derivatives [Member] | Precious metals [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 3 [Member] | Derivative financial assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	391		346
Level 3 [Member] | Derivative financial assets [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	1		2
Level 3 [Member] | Derivative financial assets [Member] | Foreign exchange contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	18		16
Level 3 [Member] | Derivative financial assets [Member] | Equity contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	159		119
Level 3 [Member] | Derivative financial assets [Member] | Precious metals contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	0		0
Level 3 [Member] | Derivative financial assets [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	208		209
Level 3 [Member] | Derivative financial assets [Member] | Other Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4],[5]	5
Level 3 [Member] | Derivative financial assets [Member] | Derivatives netting [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	0		0
Level 3 [Member] | Securities available-for-sale [Member] | U.S. Treasury, U.S. Government agencies and sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 3 [Member] | Securities available-for-sale [Member] | Obligations of U.S. states and political subdivision [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				0
Level 3 [Member] | Securities available-for-sale [Member] | Foreign debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 3 [Member] | Securities available-for-sale [Member] | Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 3 [Member] | Securities available-for-sale [Member] | Commercial Mortgage Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				0
Level 3 [Member] | Securities available-for-sale [Member] | Home Equity Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0		0
Level 3 [Member] | Securities available-for-sale [Member] | Other securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		105		0
Loans Receivable [Member] | Estimate of fair value [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[8]	725		151
Net Balance, Assets	[8]	725		151
Loans Receivable [Member] | Level 1 [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[8]	0		0
Loans Receivable [Member] | Level 2 [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[8]	725		151
Loans Receivable [Member] | Level 3 [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[8]	0		0
Domestic Deposits [Member] | Estimate of fair value [Member] | Domestic Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[6]	7,526		6,919
Net Balance, Liabilities	[6]	7,526		6,919
Domestic Deposits [Member] | Level 1 [Member] | Domestic Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[6]	0		0
Domestic Deposits [Member] | Level 2 [Member] | Domestic Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[6]	6,119		5,052
Domestic Deposits [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[7],[9]	1,407		1,867
Domestic Deposits [Member] | Level 3 [Member] | Domestic Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[6]	1,407		1,867
Long-term debt [Member] | Estimate of fair value [Member] | Short-term borrowings [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[6]	2,672		1,976
Netting Liabilities	[3],[6]	0		0
Net Balance, Liabilities	[6]	2,672		1,976
Long-term debt [Member] | Estimate of fair value [Member] | Long-term Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[6]	10,384		9,171
Netting Liabilities	[3],[6]	0
Net Balance, Liabilities	[6]	10,384		9,171
Long-term debt [Member] | Level 1 [Member] | Short-term borrowings [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[6]	0		0
Long-term debt [Member] | Level 1 [Member] | Long-term Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[6]	0		0
Long-term debt [Member] | Level 2 [Member] | Short-term borrowings [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[6]	2,672		1,976
Long-term debt [Member] | Level 2 [Member] | Long-term Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[6]	9,885		8,425
Long-term debt [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[7],[9]	499		746
Long-term debt [Member] | Level 3 [Member] | Short-term borrowings [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[6]	0		0
Long-term debt [Member] | Level 3 [Member] | Long-term Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[6]	$ 499		746
Mortgage servicing rights [Member] | Estimate of fair value [Member] | Mortgage servicing rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[10]			140
Net Balance, Assets	[10]			140
Mortgage servicing rights [Member] | Level 1 [Member] | Mortgage servicing rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[10]			0
Mortgage servicing rights [Member] | Level 2 [Member] | Mortgage servicing rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[10]			0
Mortgage servicing rights [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets				140
Mortgage servicing rights [Member] | Level 3 [Member] | Mortgage servicing rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[10]			$ 140

[1] Netting is performed at a counterparty level in cases where enforceable master netting agreements are in place, regardless of the type of derivative instrument. Therefore, we have not attempted to allocate netting to the different types of derivative instruments shown in the table above.

[2] Represents the netting of derivative receivable and payable balances for the same counterparty under enforceable netting agreements.

[3] Represents counterparty and cash collateral netting which allow the offsetting of amounts relating to certain contracts if certain conditions are met.

[4] Includes trading derivative assets of $4,411 million and $5,150 million and trading derivative liabilities of $3,786 million and $6,406 million at December 31, 2016 and 2015, respectively, as well as derivatives held for hedging and commitments accounted for as derivatives.

[5] Consists of swap agreements entered into in conjunction with the sale of certain Visa Class B Shares.

[6] See Note 15, "Fair Value Option," for additional information.

[7] We are the client-facing entity and we enter into identical but opposite derivatives to transfer the resultant risks to our affiliates. With the exception of counterparty credit risks, we are market neutral. The corresponding intra-group derivatives are presented as equity derivatives and foreign exchange derivatives in the table.

[8] Includes certain commercial loans held for sale which we have elected to apply the fair value option. See Note 7, "Loans Held for Sale," for further information.

[9] Structured deposits and structured notes contain embedded derivative features whose fair value measurements contain significant Level 3 inputs.

[10] See Note 9, "Intangible Assets," for additional information.