Investment Securities - Schedule of Gross Realized Gains and Losses on Available-for-Sale Securities and OTTI Recognized in Earnings (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Realized gains (losses):
Gross realized gains	$ 3	$ 16	$ 20	$ 50
Gross realized losses	0	(10)	(16)	(32)
Net realized gains	3	6	4	18
OTTI recognized in earnings:
Credit-related OTTI	(5)	(3)	(22)	(8)
Intent to Sell OTTI	0	(6)	(5)	(7)
Total OTTI recognized in earnings	(5)	(9)	(27)	(15)
Net securities (losses) gains	(2)	(3)	(23)	3
Proceeds from sales	$ 898	$ 3,268	$ 3,211	$ 6,827

Other than Temporary Impairment, Credit Losses Recognized In Earnings, Additions

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Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities, Intent to Sell

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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. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

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-Publisher FASB

-Name Accounting Standards Codification

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This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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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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This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities and excluding other than temporary impairments (OTTI), if any, recognized elsewhere.

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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 cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.

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-Publisher FASB

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