Fair Value Measurements - Assets and Liabilities Recorded at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions		Jun. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Netting, Assets	[1],[2]	$ (36,789)	$ (51,111)
Netting Liabilities	[1],[2]	(36,789)	(51,111)
Trading assets		20,192	16,850
Trading liabilities		4,209	4,908
Precious metals [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading assets		8,365	1,772
Trading liabilities		0	62
Other asset-backed securities available-for-sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading assets		12	15
Derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading liabilities		3,188	3,786
Derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Trading assets		3,222	4,411
Estimate of fair value [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		95,584	112,104
Netting, Assets	[3]	(41,306)	(56,256)
Net Balance, Assets		54,278	55,848
Gross Balance, Liabilities		66,858	81,176
Netting Liabilities	[3]	(39,991)	(54,937)
Net Balance, Liabilities		26,867	26,239
Estimate of fair value [Member] | Trading liabilities excluding derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities		1,021	1,122
Net Balance, Liabilities		1,021	1,122
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]	43,607	59,472
Netting Liabilities	[3],[4]	(39,991)	(54,937)
Net Balance, Liabilities	[4]	3,616	4,535
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]	23,879	32,652
Netting Liabilities	[3],[4]	0	0
Net Balance, Liabilities	[4]	23,879	32,652
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]	16,005	22,682
Netting Liabilities	[3],[4]	0	0
Net Balance, Liabilities	[4]	16,005	22,682
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]	2,075	1,875
Netting Liabilities	[3],[4]	0	0
Net Balance, Liabilities	[4]	2,075	1,875
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]	510	880
Netting Liabilities	[3],[4]	0	0
Net Balance, Liabilities	[4]	510	880
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]	1,088	1,369
Netting Liabilities	[3],[4]	0	0
Net Balance, Liabilities	[4]	1,088	1,369
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]	50	14
Netting Liabilities	[3],[4],[5]	0	0
Net Balance, Liabilities	[4],[5]	50	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]	(39,991)	(54,937)
Net Balance, Liabilities	[4]	(39,991)	(54,937)
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]	864	770
Net Balance, Assets	[6]	864	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		4,844	3,806
Net Balance, Assets		4,844	3,806
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		131	184
Net Balance, Assets		131	184
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		81	96
Net Balance, Assets		81	96
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		91	85
Net Balance, Assets		91	85
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		1,803	2,884
Net Balance, Assets		1,803	2,884
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		1,643	3,597
Net Balance, Assets		1,643	3,597
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		12	15
Net Balance, Assets		12	15
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		8,365	1,772
Net Balance, Assets		8,365	1,772
Estimate of fair value [Member] | Derivative financial assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	45,046	61,260
Netting, Assets	[3],[4]	(41,306)	(56,256)
Net Balance, Assets	[4]	3,740	5,004
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]	23,350	32,200
Netting, Assets	[3],[4]	0	0
Net Balance, Assets	[4]	23,350	32,200
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]	17,035	24,056
Netting, Assets	[3],[4]	0	0
Net Balance, Assets	[4]	17,035	24,056
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]	2,855	2,330
Netting, Assets	[3],[4]	0	0
Net Balance, Assets	[4]	2,855	2,330
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]	589	1,119
Netting, Assets	[3],[4]	0	0
Net Balance, Assets	[4]	589	1,119
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]	1,211	1,550
Netting, Assets	[3],[4]	0	0
Net Balance, Assets	[4]	1,211	1,550
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]	6	5
Netting, Assets	[3],[4],[5]	0	0
Net Balance, Assets	[4],[5]	6	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]	(41,306)	(56,256)
Net Balance, Assets	[4]	(41,306)	(56,256)
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		31,185	36,069
Net Balance, Assets		31,185	36,069
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		412	521
Net Balance, Assets		412	521
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	154
Net Balance, Assets		154	154
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		56	61
Net Balance, Assets		56	61
Estimate of fair value [Member] | Securities available-for-sale [Member] | Other asset-backed securities available-for-sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		508	105
Net Balance, Assets		508	105
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		26,083	28,846
Gross Balance, Liabilities		1,132	1,163
Level 1 [Member] | Trading liabilities excluding derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities		980	1,060
Level 1 [Member] | Derivative Financial Instruments, Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	152	103
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]	94	84
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]	35	6
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]	23	13
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	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	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		4,610	3,560
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		471	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]	129	141
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]	51	36
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]	37	24
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]	41	81
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	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		20,873	25,145
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] | 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 asset-backed securities available-for-sale [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		67,159	79,694
Gross Balance, Liabilities		63,873	77,899
Level 2 [Member] | Trading liabilities excluding derivatives [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities		41	62
Level 2 [Member] | Derivative Financial Instruments, Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[4]	43,285	59,161
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]	23,785	32,568
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]	15,968	22,658
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]	1,964	1,714
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]	487	867
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]	1,081	1,354
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	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]	864	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		234	246
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		81	96
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		91	85
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		1,172	3,597
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		12	15
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		8,365	1,772
Level 2 [Member] | Derivative financial assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets	[4]	44,616	60,728
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]	23,299	32,163
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]	16,996	24,014
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]	2,712	2,171
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]	548	1,038
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]	1,061	1,342
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	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		10,312	10,924
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		412	521
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	154
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		56	61
Level 2 [Member] | Securities available-for-sale [Member] | Other asset-backed securities available-for-sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		401	0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		2,342	3,564
Gross Balance, Liabilities		1,853	2,114
Level 3 [Member] | Collateralized debt obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		131	184
Level 3 [Member] | Corporate and other domestic debt securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		1,803	2,884
Level 3 [Member] | Other asset-backed securities available-for-sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		107	105
Level 3 [Member] | Interest rate contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		0	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	[7]	32	(2)
Level 3 [Member] | Credit contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		143	193
Level 3 [Member] | Other Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		(44)	(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]	170	208
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	0
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]	2	18
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]	111	161
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]	7	15
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]	50	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	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] | Collateralized debt obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		131	184
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		1,803	2,884
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	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]	301	391
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]	0	1
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]	2	18
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]	143	159
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]	150	208
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]	6	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] | 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] | 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 asset-backed securities available-for-sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Assets		107	105
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]	389	725
Net Balance, Assets	[8]	389	725
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]	389	725
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]	7,487	7,526
Net Balance, Liabilities	[6]	7,487	7,526
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]	6,345	6,119
Domestic Deposits [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[7],[9]	1,142	1,407
Domestic Deposits [Member] | Level 3 [Member] | Domestic Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[6]	1,142	1,407
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]	2,818	2,672
Netting Liabilities	[3],[6]	0	0
Net Balance, Liabilities	[6]	2,818	2,672
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]	11,925	10,384
Netting Liabilities	[3],[6]	0
Net Balance, Liabilities	[6]	11,925	10,384
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]	2,818	2,672
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]	11,384	9,885
Long-term debt [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Gross Balance, Liabilities	[7],[9]	541	499
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]	$ 541	$ 499

[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 $3,222 million and $4,411 million and trading derivative liabilities of $3,188 million and $3,786 million at June 30, 2017 and December 31, 2016, 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 sales of certain Visa Class B Shares.

[6] See Note 9, "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 6, "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.