Fair Value (Schedule Of Assets And Liabilities Measured At Fair Value By Class On A Recurring Basis) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	$ 13,725	$ 14,737
Trading account, at fair value	182	106
Assets, Fair Value Disclosure	14,832	15,619
Securities sold, not yet purchased	66	85
Financial and Nonfinancial Liabilities, Fair Value Disclosure	198	219
Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total net gains (losses) included in, Purchases	10	11
Servicing Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total net gains (losses) included in, Purchases	0	0
US Treasury Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	12,381	13,425
Available-for-sale Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	1,319	1,291
Asset-backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	25	21
Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	4	4
Other liabilities	4	2
Bank-owned life insurance [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments	525	516
Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments	116	102
Assets, Fair Value Disclosure	1	1
Interest-Only-Strip [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	18	18
Derivative Interest Rate Related And Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	146	40
Other liabilities	14	36
Interest Rate Swaps [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	3	1
Other liabilities	1	1
Warranty, Rights and Obligations, Fair Value Option [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	113	95
Other liabilities	113	95
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	25	40
Trading account, at fair value	65	14
Assets, Fair Value Disclosure	216	153
Securities sold, not yet purchased	66	85
Financial and Nonfinancial Liabilities, Fair Value Disclosure	183	182
Level 1 [Member] \| US Treasury Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	25	40
Level 1 [Member] \| Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	4	4
Other liabilities	4	2
Level 1 [Member] \| Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments	9
Assets, Fair Value Disclosure	0	0
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	13,700	14,697
Trading account, at fair value	117	92
Assets, Fair Value Disclosure	14,491	15,346
Securities sold, not yet purchased	0	0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	15	37
Level 2 [Member] \| US Treasury Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	12,356	13,385
Level 2 [Member] \| Available-for-sale Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	1,319	1,291
Level 2 [Member] \| Asset-backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	25	21
Level 2 [Member] \| Bank-owned life insurance [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments	525	516
Level 2 [Member] \| Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments
Assets, Fair Value Disclosure	0	0
Level 2 [Member] \| Derivative Interest Rate Related And Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	3	1
Other liabilities	1	1
Level 2 [Member] \| Interest Rate Swaps For Customers [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	146	40
Other liabilities	14	36
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	0	0
Assets, Fair Value Disclosure	125	120
Securities sold, not yet purchased	0	0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member] \| US Treasury Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities	0	0
Fair Value, Inputs, Level 3 [Member] \| Available-for-sale Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities
Fair Value, Inputs, Level 3 [Member] \| Asset-backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investment securities
Fair Value, Inputs, Level 3 [Member] \| Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other noninterest-bearing investments	107	102
Assets, Fair Value Disclosure	1	1
Fair Value, Inputs, Level 3 [Member] \| Interest-Only-Strip [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	18	18
Deferred Compensation Arrangement with Individual, by Type of Compensation, Pension and Other Postretirement Benefits [Member] \| Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets		95
Deferred Compensation Arrangement with Individual, by Type of Compensation, Pension and Other Postretirement Benefits [Member] \| Level 1 [Member] \| Warranty, Rights and Obligations, Fair Value Option [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other assets	113
Other liabilities	$ 113	$ 95

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
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Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Fair value of obligations incurred from short sales.

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-Publisher FASB
-Name Accounting Standards Codification
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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Fair value portion of other assets.

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Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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