Investment securities available for sale transferred to held to maturity amortized cost at date of transfer.

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Investment securities available for sale transferred to held to maturity fair value at date of transfer.

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Mortgage Back Securities, Held-To-Maturity, Reclassified To Available-For-Sale

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Mortgage Backed Securities, Available-For-Sale, Weighted Average Term

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Other Comprehensive Income Loss Unrealized Losses On Securities Available For Sale Transferred To Held To Maturity Arising During Period Before Tax

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Other Comprehensive Income Loss Unrealized Losses On Securities Available For Sale Transferred To Held To Maturity Arising During Period Net Of Tax

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Unrealized Losses Related to Marketability of Securities or Issuer's Ability to Honor Redemption Obligations

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Number of investment positions in available-for-sale investments that have been in a continuous unrealized loss position for greater than or equal to a year for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

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Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer.

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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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Value of the investment at close of period. For schedules of investments that are categorized, the value would be aggregated by category. For investment in and advances to affiliates, if operations of any controlled companies are different in character from those of the company, group such affiliates within divisions and by type of activities.

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Balance held at close of period in number of shares.

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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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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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Investments (Narrative) (Details) shares in Thousands			12 Months Ended
Investments (Narrative) (Details) shares in Thousands	Nov. 01, 2019 USD ($)	May 01, 2018 USD ($)	Dec. 31, 2019 USD ($) investments investment	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($)
Schedule of Investments [Line Items]
Investment securities available for sale transferred to held to maturity fair value, net of tax		$ 109,500,000	$ 72,512,000	$ (109,507,000)	$ 0
Reclassification of unrealized losses, net of tax		84,300,000	$ 71,149,000	(71,149,000)	$ 0
Number of investments in continuous unrealized loss position for more than twelve months \| investment			91
Unrealized losses related to marketability of securities or issuers ability to honor redemption obligations			$ 0
Investment value deemed to be OTTI			0
Investment securities, aggregate carrying value, pledged as collateral			$ 3,930,000,000	$ 4,030,000,000.00
Visa Class B Common Stock
Schedule of Investments [Line Items]
Investment owned (in shares) \| shares				298
Investment owned, fair value				$ 0
Mortgage Backed Securities
Schedule of Investments [Line Items]
Investment securities available for sale transferred to held to maturity fair value		2,380,000,000
Investment securities available for sale transferred to held to maturity amortized cost		$ 2,490,000,000
Weighted average contractual maturity (years)		13 years
Available-for-sale, securities in unrealized loss positions, number of positions, greater than or equal to on year \| investments			90
Corporate Bonds
Schedule of Investments [Line Items]
Available-for-sale, securities in unrealized loss positions, number of positions, greater than or equal to on year \| investments			1
Accounting Standards Update 2019-04 \| Mortgage Backed Securities
Schedule of Investments [Line Items]
Mortgage backed securities, held-to-maturity, transferred to available-for-sale	$ 2,080,000,000.00
Investment securities available for sale transferred to held to maturity fair value	2,150,000,000
Investment securities available for sale transferred to held to maturity fair value, net of tax	72,500,000
Reclassification of unrealized losses, net of tax	$ 55,800,000