Accumulated Other Comprehensive Income (Loss) - Reclassifications Out of AOCI (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gains on sales of debt securities	$ 1,271		$ 1,662		$ 3,374
Other-than-temporary impairment	(21)		(57)		(360)
Equity investment income	2,901		2,070		7,360
Net interest income	42,265		40,656		44,616
Trading account profits	7,056		5,870		6,697
Other income (loss)	(29)		(2,034)		8,215
Personnel	34,719		35,648		36,965
Income tax expense (benefit)	4,741		(1,116)		(1,676)
Net income	11,431	[1]	4,188	[1]	1,446	[1]
Debt Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gains on sales of debt securities	1,271		1,662		3,374
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	624		67		4,840
Reclassification out of Accumulated Other Comprehensive Income [Member] | Available-for- Sale Securities [Member] | Debt Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gains on sales of debt securities	1,271		1,662		3,374
Other-than-temporary impairment	(20)		(53)		(299)
Income before income taxes	1,251		1,609		3,075
Income tax expense (benefit)	463		595		1,138
Net income	788		1,014		1,937
Reclassification out of Accumulated Other Comprehensive Income [Member] | Available-for- Sale Securities [Member] | Equity Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Equity investment income	771		19		6,501
Income before income taxes	771		19		6,501
Income tax expense (benefit)	285		7		2,384
Net income	486		12		4,117
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	(773)		(1,035)		(1,617)
Income tax expense (benefit)	(286)		(383)		(599)
Net income	(487)		(652)		(1,018)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member] | Interest Rate Contract [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net interest income	(1,119)		(956)		(1,393)
Other income (loss)	18		0		0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member] | Commodity Contract [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Trading account profits	(1)		(1)		7
Reclassification out of Accumulated Other Comprehensive Income [Member] | Derivatives [Member] | Equity Contract [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Personnel	329		(78)		(231)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Employee Benefit Plans [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	(237)		(539)		(437)
Income tax expense (benefit)	(79)		(212)		(167)
Net income	(158)		(327)		(270)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Employee Benefit Plans [Member] | Prior Service Costs [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Personnel	(4)		(6)		(16)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Employee Benefit Plans [Member] | Transition Obligation [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Personnel	0		(32)		(31)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Employee Benefit Plans [Member] | Actuarial Losses [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Personnel	(225)		(443)		(387)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Employee Benefit Plans [Member] | Settlements and Curtailments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Personnel	(8)		(58)		(3)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Foreign Currency [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other income (loss)	(138)		30		65
Income before income taxes	(138)		30		65
Income tax expense (benefit)	(133)		10		(9)
Net income	$ (5)		$ 20		$ 74

[1] There were no material intersegment revenues.