Accumulated Other Comprehensive Income (Loss) - Impact to Net Income for Items Reclassified out of Accumulated Other Comprehensive Income and into Earnings (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Realized gains (losses) on sale of securities	$ 4		$ 7
Amortization of unrealized gains on securities transferred from available-for-sale to held-to-maturity, Interest income	3,252	$ 3,068	6,473	$ 6,129
Realized gains (losses) on derivative hedges	2,845	2,716	5,680	5,414
Actuarial gains (losses) and prior service cost (credit) amortization	(278)	(293)	(578)	(610)
Total securities gains (losses), net	3		6
Applicable income taxes	(542)	(528)	(1,046)	(1,007)
Net income	1,536	1,497	2,937	2,941
Reclassification Out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	(41)	(60)	(88)	(121)
Reclassification Out of Accumulated Other Comprehensive Income [Member] \| Unrealized Gains (Losses) on Securities Available-For-Sale [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Realized gains (losses) on sale of securities	4		7
Other-than-temporary impairment recognized in earnings	(1)		(1)
Total securities gains (losses), net	3		6
Applicable income taxes	(1)		(2)
Net income	2		4
Reclassification Out of Accumulated Other Comprehensive Income [Member] \| Unrealized Gains (Losses) on Securities Transferred From Available For Sale to Held To Maturity [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of unrealized gains on securities transferred from available-for-sale to held-to-maturity, Interest income	4	7	9	14
Applicable income taxes	(2)	(2)	(4)	(5)
Net income	2	5	5	9
Reclassification Out of Accumulated Other Comprehensive Income [Member] \| Unrealized Gains (Losses) on Derivative Hedges [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Realized gains (losses) on derivative hedges	(33)	(49)	(76)	(99)
Applicable income taxes	13	19	29	38
Net income	(20)	(30)	(47)	(61)
Reclassification Out of Accumulated Other Comprehensive Income [Member] \| Unrealized Gains (Losses) on Retirement Plans [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Actuarial gains (losses) and prior service cost (credit) amortization	(40)	(56)	(81)	(112)
Applicable income taxes	15	21	31	43
Net income	$ (25)	$ (35)	$ (50)	$ (69)

This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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The net amount of operating interest income (expense).

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The amount of other than temporary impairment losses on investments in debt and equity securities categorized as Available-for-sale which have been recognized in earnings during the period. Such impairment losses consist of other than temporary impairments (OTTI) on equity securities, credit losses on investments in debt securities, and when the entity intends to sell an impaired debt security or it is more likely than not that the entity will be required to sell the impaired debt security before recovery of its amortized cost basis.

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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

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