Basis of Presentation and Accounting Policies (Details) - USD ($) $ in Millions		3 Months Ended
Jan. 01, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings		$ 193
Equity securities, available-for-sale, at fair value (cost of $0 and $140)		0		$ 154
Fee income and other		231	$ 221
Equity Securities [Member]
Equity securities, available-for-sale, at fair value (cost of $0 and $140)		154		$ 154
Accumulated Net Unrealized Investment Gain (Loss)
OCI, before Reclassifications	$ 11	(301)	58
Fee Income [Member] \| Other fee revenues [Member]
Fee income and other		$ 25	$ 15

Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings

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- Definition

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
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Amount of fees and commissions from financial services and banking activities and correspondent clearing. Includes fees from depositor accounts, credit cards, merchant discounts, and fiduciary and trust activities, guarantee fees, investment advisory, management, and administrative fees, transfer agent fees, and insurance commissions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-SubTopic 225
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Amount after tax, before reclassification adjustments, of other comprehensive income (loss), attributable to parent.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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