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Disclosure regarding factors used to determine that the impairment of securities categorized as held-to-maturity or available-for-sale where cost exceeds fair value is not an other than temporary impairment (OTTI). This item contains disclosure of the number of investment positions in the held-to-maturity and available-for-sale investments determined to be temporarily impaired.

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- Definition

Debt Securities, Available-For-Sale, Securities Transferred, Security Term

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- Definition

Debt Securities, Available-For-Sale, Sold Security, at Carrying Value

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- Definition

Debt Securities, Available-For-Sale, Transferred Security, At Carrying Value

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- Definition

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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-Publisher FASB
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- Definition

Amount of equity securities categorized neither as held-to-maturity nor as trading.

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- Definition

Maximum amount of loss due to credit risk that, based on the gross fair value of the financial instrument, the entity would incur if parties to the financial instruments that make up the concentration failed completely to perform according to the terms of the contracts and the collateral or other security, if any, for the amount due proved to be of no value to the entity.

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- Definition

Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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- Definition

Amount of unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

No definition available.

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- Definition

Amount of investment in debt security measured at amortized cost (held-to-maturity).

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- Definition

Amount of gain (loss) on sale of investment in debt security measured at amortized cost (held-to-maturity), including other-than-temporary impairment (OTTI).

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- Definition

The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

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- Definition

Amount of unrealized gain (loss) on investment in marketable security, excluding other-than-temporary impairment (OTTI).

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- Definition

Investment in short-term money-market instruments (such as commercial paper, banker's acceptances, repurchase agreements, government securities, certificates of deposit, and so forth) which are highly liquid (that is, readily convertible to known amounts of cash) and so near their maturity that they present an insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify as cash equivalents by definition. Original maturity means an original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Sum of the carrying amounts as of the date of the latest financial statement presented of securities which are owned but transferred to another party to serve as collateral to partially or fully secure a debt obligation, repurchase agreement or other current or potential obligation, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party.

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Investment Securities - Narrative (Details)	12 Months Ended
Investment Securities - Narrative (Details)	Dec. 31, 2018 USD ($) security	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jan. 01, 2018 USD ($)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Pledged securities not separately reported	$ 39,000,000,000	$ 48,000,000,000
Investment securities available-for-sale	45,148,000,000	57,121,000,000
Debt securities, held-to-maturity	41,914,000,000	40,458,000,000
Debt securities, available-for-sale, transferred security, at carrying value	2,100,000,000	496,000,000
Debt securities, available-for-sale, unrealized gain (loss)	53,000,000	2,800,000
Losses from other-than-temporary impairment	3,000,000	0	$ 3,000,000
Gross pre-tax unrealized losses	$ 1,056,000,000
Number of securities in loss position \| security	1,129
Agency Securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Losses from other-than-temporary impairment	$ 0	0	0
US Treasury and federal agencies, mortgage-backed securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Investment securities available-for-sale	15,968,000,000	10,872,000,000
Debt securities, held-to-maturity	21,647,000,000	16,651,000,000
Securities sold	26,000,000,000	12,200,000,000
Pre-tax gain on sale of securities	9,000,000	39,000,000
Federal family education loan program
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Losses from other-than-temporary impairment	$ 0	0	0
Asset backed securities, average remaining,term	5 years
Asset-backed securities, student loans
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Investment securities available-for-sale	$ 541,000,000	3,358,000,000
Debt securities, held-to-maturity	3,191,000,000	3,047,000,000
Losses from other-than-temporary impairment	0	0	0
Total exposure (less than)	4,000,000
Non-U.S. debt securities, mortgage-backed securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Investment securities available-for-sale	1,682,000,000	6,695,000,000
Debt securities, held-to-maturity	638,000,000	939,000,000
Losses from other-than-temporary impairment	3,000,000	1,000,000	2,000,000
State and political subdivisions
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Investment securities available-for-sale	1,918,000,000	9,151,000,000
Losses from other-than-temporary impairment	0	0	0
Residential Mortgage Backed Securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Losses from other-than-temporary impairment	0	0	0
Commercial Mortgage Backed Securities
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Losses from other-than-temporary impairment	$ 0	$ 0	$ 1,000,000
Minimum
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Debt securities, available-for-sale, security term	10 years
Maximum
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Debt securities, available-for-sale, security term	42 years
Accounting Standards Update 2016-01
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Money market funds reclassified				$ 397,000,000
Available-for-sale equity securities reclassified				$ 46,000,000
Accounting Standards Update 2017-12
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Investment securities available-for-sale	$ 1,200,000,000
Debt securities, held-to-maturity	(1,200,000,000)
Loss from sale of HTM securities	$ (36,000,000)