Zions Bancorporation, National Association (ZION) 10-Q 8 May 19 2019 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 30, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Trading Symbol	zion
Entity Registrant Name	ZIONS BANCORPORATION, NATIONAL ASSOCIATION /UT/
Entity Central Index Key	0000109380
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	182,512,940	182,565,329
Entity Emerging Growth Company	false
Entity Small Business	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) shares in Thousands, $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Debt Securities, Held-to-maturity, Fair Value	$ 762
ASSETS
Cash and due from banks	536	$ 614
Money market investments:
Interest-bearing deposits	702	619
Federal funds sold and security resell agreements	438	1,461
Investment securities:
Available-for-sale, at fair value	14,904	14,737
Trading account, at fair value	316	106
Total investment securities	15,984	15,617
Loans held for sale	69	93
Loans held for investment, net of allowance
Loans and leases, net of unearned income and fees	47,606	46,714
Less allowance for loan losses	497	495
Loans held for investment, net of allowance	47,109	46,219
Other noninterest-bearing investments	993	1,046
Premises, equipment and software, net	1,125	1,124
Goodwill and intangibles	1,014	1,015
Other real estate owned	6	4
Other assets	1,219	934
Total assets	69,195	68,746
LIABILITIES AND SHAREHOLDERS' EQUITY
Noninterest-bearing demand	23,259	23,645
Interest-bearing:
Savings and money market	26,348	26,120
Total deposits	54,535	54,101
Federal funds purchased and other short-term borrowings	4,944	5,653
Long-term Debt	1,228	724
Reserve for unfunded lending commitments	59	57
Other liabilities	841	633
Total liabilities	61,607	61,168
Shareholders' equity:
Preferred stock, without par value	566	566
Common Stock	0	0
Additional Paid-in Capital	3,541	3,806
Retained earnings	3,603	3,456
Accumulated other comprehensive income (loss)	(122)	(250)
Stockholders' Equity	7,588	7,578
Total liabilities and shareholders' equity	$ 69,195	$ 68,746
Preferred Stock, Shares Authorized	4,400	4,400
Common Stock, Shares Authorized	350,000	350,000
Common Stock, Shares, Issued	182,513	187,554
Common Stock, Shares, Outstanding	182,513	187,554
Fair Value, Inputs, Level 2 [Member]
Investment securities:
Held-to-maturity, at amortized cost	$ 764	$ 774
Trading account, at fair value	155	92
Interest-bearing:
Time	4,928	4,336
Long-term Debt	1,228	724
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Held-to-maturity, Fair Value	762	767
Interest-bearing:
Time	4,921	4,319
Long-term Debt	$ 1,240	$ 727

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Preferred Stock, Shares Authorized	4,400	4,400
Common Stock, Shares Authorized	350,000	350,000
Common Stock, Par or Stated Value Per Share	$ 0.0010
Common Stock, Shares, Issued	182,513	187,554
Held-to-maturity, fair value	$ 762
Common stock, outstanding shares	182,513	187,554
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Held-to-maturity, fair value	$ 762	$ 767

Consolidated Statements Of Inco

Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Interest income:
Interest and Fees and Loans	$ 570	$ 497
Interest on Money Market Investments	9	6
Interest on Securities	96	86
Total Interest Income	675	589
Interest expense:
Interest on Deposits	57	20
Interest on short- and long-term borrowings	42	27
Total Interest Expense	99	47
Net interest income	576	542
Provision for loan losses	2	(40)
Provision for unfunded lending commitments	2	(7)
Provision for Credit Losses	4	(47)
Net interest income after provision for loan losses	572	589
Noninterest income:
Service charges and fees on deposit accounts	40	42
Other service charges, commissions, and fees	54	55
Wealth management and trust income	13	12
Loan Sales and Servicing Income	5	6
Capital markets and foreign exchange	8	8
Customer-related Fees	120	123
Dividends and Other Investment Income	9	11
Securities Gains, Net	1	0
Other	2	4
Noninterest Income	132	138
Noninterest expense:
Salaries and Employee Benefits	287	269
Occupancy, Net	33	31
Furniture, Equipment, and Software, Net	32	33
Other real estate expense, net	1	0
Credit-Related Expense	6	7
Professional and Legal Fees	11	12
Advertising	5	5
FDIC Premiums	6	13
Other	51	49
Total Noninterest Expense	430	419
Income Before Income Taxes	274	308
Income taxes	61	70
Net income	213	238
Preferred Stock Dividends	(8)	(7)
Net Earnings Available to Common Shareholders	$ 205	$ 231
Weighted average common shares outstanding during the period:
Weighted Average Number of Shares Outstanding, Basic	184,767	196,722
Weighted Average Number of Shares Outstanding, Diluted	195,241	210,243
Earnings Per Share, Basic	$ 1.10	$ 1.16
Earnings Per Share, Diluted	$ 1.04	$ 1.09

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net income for the period	$ 213	$ 238
Other comprehensive income (loss), net of tax:
Unrealized holding gains (losses) on investment securities	122	(126)
Net unrealized gains (losses) on other noninterest-bearing investments	(3)	1
Net unrealized holding gains (losses) on derivative instruments	8	(3)
Reclassification adjustment for decrease in interest income recognized in earnings on derivatives instruments	1	0
Other comprehensive income (loss)	128	(128)
Comprehensive income	$ 341	$ 110

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Shareholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity	$ 7,679	$ 566	$ 4,445		$ 2,807	$ (139)
Additional Paid-in Capital				$ 0
Balance (in shares) at Dec. 31, 2017			197,532
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income for the period	238				238
Other comprehensive income, net of tax	(128)					(128)
Preferred Stock Redemption	1				1
Stock Issued During Period, Value, Conversion of Convertible Securities
Stock Repurchased and Retired During Period, Value	115
Common Stock Repurchased, Accumulated Paid-in Capital	$ (122)		$ (122)
Net Shares Issued From Stock Warrant Exercises			1,042
Company Common Stock Repurchased, Shares	2,200		(2,277)
Net activity under employee plans and related tax benefits	$ 23		$ 23
Net activity under employee plans and related tax benefits, shares			753
Dividends on preferred stock	(7)				(7)
Dividends on common stock	(40)				(40)
Balance (in shares) at Mar. 31, 2018			197,050
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity	7,644	566	$ 4,346		2,999	(267)
Additional Paid-in Capital				0
Stockholders' Equity	7,578	566	$ 0		3,456	(250)
Additional Paid-in Capital	$ 3,806			3,806
Balance (in shares) at Dec. 31, 2018	187,554		187,554
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income for the period	$ 213				213
Other comprehensive income, net of tax	128					128
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	(3)				(3)
Stock Repurchased and Retired During Period, Value	275
Common Stock Repurchased, Accumulated Paid-in Capital	(276)			(276)
Net Shares Issued From Stock Warrant Exercises			1
Stock Issued During Period, Value, Stock Options Exercised
Company Common Stock Repurchased, Shares	5,500		(5,506)
Net activity under employee plans and related tax benefits	$ 11
Employee Plans, Accumulated Paid-in Capital				11
Net activity under employee plans and related tax benefits, shares			464
Dividends on preferred stock	(7)				(7)
Dividends on common stock	$ (56)				(56)
Balance (in shares) at Mar. 31, 2019	182,513		182,513
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity	$ 7,588	$ 566	$ 0		$ 3,603	$ (122)
Additional Paid-in Capital	$ 3,541			$ 3,541

Consolidated Statements Of Ch_2

Consolidated Statements Of Changes In Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Common Stock, Dividends, Per Share, Declared	$ 0.30	$ 0.20

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Cash Flows [Abstract]
Net increase (decrease) in cash and due from banks	$ (78)	$ (78)
Cash and due from banks at beginning of period	614	548
Cash and due from banks at end of period	536	470
Cash paid for interest	95	44
Net cash paid for income taxes	(2)	1
CASH FLOWS FROM OPERATING ACTIVITIES
Net income for the period	213	238
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Provision for credit losses	4	(47)
Depreciation and amortization	44	43
Share-based Compensation	14	13
Deferred income tax expense	15	13
Net decrease (increase) in trading securities	(210)	4
Net increase in loans held for sale	(1)	(33)
Debt and Equity Securities, Gain (Loss)	(1)	0
Change in other liabilities	(43)	4
Change in other assets	(70)	48
Other, net	(8)	(8)
Net cash provided by (used in) operating activities	(42)	275
CASH FLOWS FROM INVESTING ACTIVITIES
Net decrease (increase) in money market investments	940	(117)
Proceeds from maturities and paydowns of investment securities held-to-maturity	101	59
Purchases of investment securities held-to-maturity	(91)	(57)
Proceeds from sales, maturities, and paydowns of investment securities available-for-sale	587	669
Purchases of investment securities available-for-sale	(623)	(612)
Net change in loans and leases	(860)	(311)
Purchases and sales of other noninterest-bearing investments	54	(31)
Purchases of premises and equipment	(25)	(28)
Other, net	4	(1)
Net Cash Provided by (Used in) Investing Activities	87	(429)
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase in deposits	435	347
Net change in short-term funds borrowed	(709)	1,890
Repayments of debt over 90 days and up to one year	0	(2,000)
Proceeds from the issuance of long-term debt	497	0
Proceeds from Issuance of Common Stock	4	10
Dividends paid on common and preferred stock	(66)	(49)
Bank common stock repurchased	(276)	(122)
Other, net	(8)	0
Net cash provided by (used in) financing activities	(123)	76
Loans Held for Investment Transferred to Other Real Estate Owned	5	3
Loans Held for Investment Reclassified to Loans Held for Sale, Net	$ 0	$ (15)

Basis of Presentaion

Basis of Presentaion	3 Months Ended
	Mar. 31, 2019
Basis Of Presentation [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	BASIS OF PRESENTATION The accompanying unaudited consolidated financial statements of Zions Bancorporation, National Association and its majority-owned subsidiaries (collectively “Zions Bancorporation, N.A.,” “the Bank,” “we,” “our,” “us”) have been prepared in accordance with United States (“U.S.”) generally accepted accounting principles (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. References to GAAP, including standards promulgated by the Financial Accounting Standards Board (“FASB”), are made according to sections of the Accounting Standards Codification (“ASC”). Changes to the ASC are made with Accounting Standards Updates (“ASU”) that include consensus issues of the Emerging Issues Task Force. Operating results for the three months ended March 31, 2019 and 2018 are not necessarily indicative of the results that may be expected in future periods. In preparing the consolidated financial statements, we are required to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. The consolidated balance sheet at December 31, 2018 is from the audited financial statements at that date, but does not include all of the information and footnotes required by GAAP for complete financial statements. For further information, refer to the consolidated financial statements and footnotes thereto included in the Bank’s 2018 Annual Report on Form 10-K. Certain prior period amounts have been reclassified to conform with the current period presentation. These reclassifications did not affect net income or shareholders’ equity. Zions Bancorporation, N.A. is a commercial bank headquartered in Salt Lake City, Utah. The Bank provides a full range of banking and related services in 11 Western and Southwestern states through 7 separately managed and branded units as follows: Zions Bank, in Utah, Idaho and Wyoming; Amegy Bank (“Amegy”), in Texas; California Bank & Trust (“CB&T”); National Bank of Arizona (“NBAZ”); Nevada State Bank (“NSB”); Vectra Bank Colorado (“Vectra”), in Colorado and New Mexico; and The Commerce Bank of Washington (“TCBW”) which operates under that name in Washington and under the name The Commerce Bank of Oregon in Oregon.

Certain Recent Accounting Prono

Certain Recent Accounting Pronouncements (Notes)	3 Months Ended
	Mar. 31, 2019
Certain Recent Accounting Pronouncements [Abstract]
Certain Recent Accounting Pronouncements [Text Block]	RECENT ACCOUNTING PRONOUNCEMENTS AND DEVELOPMENTS Standard Description Date of adoption Effect on the financial statements or other significant matters Standards not yet adopted by the Bank ASU 2016-13, Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments This ASU significantly changes how entities will measure credit losses for virtually all financial assets and certain other instruments that are not measured at fair value through net income that have the contractual right to receive cash. The standard replaces today’s “incurred loss” approach with an “expected loss” model for instruments such as loans and held-to-maturity (“HTM”) securities that are measured at amortized cost. The standard requires credit losses relating to available-for sale (“AFS”) debt securities to be recorded through an allowance for credit loss (“ACL”) rather than a reduction of the carrying amount and replaces the historically required other-than-temporary impairment (“OTTI”) analysis. It also changes the accounting for purchased credit-impaired debt securities and loans. The standard retains many of the current disclosure requirements in U.S. GAAP and expands other disclosure requirements. The new guidance is effective for calendar year-end public companies beginning January 1, 2020. Early adoption is permitted as of January 1, 2019. January 1, 2020 Our implementation team, led jointly by Credit, Treasury, and the Corporate Controller’s group, has developed models to meet the new standard that are being validated. We have started to analyze the results of our models. Next steps include establishing and testing controls, further challenging model results, and finalizing the qualitative allowance process and disclosures. Based on our current analysis, we believe the standard may potentially have a material impact on the Bank’s financial statements, and we expect more volatility in the credit loss estimate over economic cycles. Transition to the new standard is through a cumulative-effect adjustment to the opening retained earnings as of the beginning of the first period of adoption, January 1, 2020. The Bank does not plan to early adopt this new guidance. ASU 2017-04, Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment This ASU removes the requirements in step two of the current goodwill impairment model, eliminating the requirement to calculate and compare the implied fair value of the reporting entity with the carrying amount of that entity, including goodwill, to measure any impairment charge. Instead, entities will record an impairment charge based on the excess of a reporting unit’s carrying amount of goodwill over its implied fair value of goodwill (i.e., measure the charge based on step one of the current guidance). The standard also continues to allow entities to perform an optional qualitative goodwill impairment assessment before determining whether to proceed to the quantitative step one. The standard is effective for the Bank as of January 1, 2020. Early adoption is allowed for any goodwill impairment test performed after January 1, 2017. January 1, 2020 We do not currently expect this guidance will have a material impact on the Bank’s financial statements since the fair values of our reporting units were not lower than their respective carrying amounts of goodwill at the time of our impairment analysis for 2018 and there were no decreases in the fair value identified for the relevant reporting units in the first quarter of 2019 and there continues to be no future expected decreases the relevant fair values in the foreseeable future. The Bank is not planning to early adopt this new guidance. The transition and adoption provisions are to be applied prospectively. Standard Description Date of adoption Effect on the financial statements or other significant matters Standards adopted by the Bank during 2019 ASU 2016-02, Leases (Topic 842) and subsequent related ASUs Although lessor accounting was left materially unchanged by ASU 2016-02 (and all related ASUs which together have been codified in ASC 842), ASC 842 requires that all lessees recognize a right-of-use asset and an offsetting lease liability for all leases with a term greater than 12 months. As the lessee, we adopted an accounting policy election, by class of underlying asset, to not recognize lease assets or liabilities for leases with a term of 12 months or less. The recognition, measurement, and presentation of expenses and cash flows arising from a lease will depend primarily on its classification as a finance or operating lease. ASC 842 requires additional disclosures to provide financial statement users a better understanding of the amount, timing, and uncertainty of cash flows arising from leases. These new quantitative and qualitative disclosure requirements are detailed further in Note 8. January 1, 2019 The Bank adopted ASC 842 at the beginning of the current quarter using the second of two permitted modified retrospective approaches for initial adoption. Under this method, the Bank recorded a right-of use asset of approximately $225 million and an offsetting lease liability of approximately $242 million. The impact to retained earnings upon adoption was not material. See Note 8 for additional details on the financial statement impact of completing the adoption of ASC 842. ASU 2017-08, Nonrefundable Fees and Other Costs (Subtopic 310-20). Premium Amortization on Purchased Callable Debt Securities The amendments in this ASU shorten the amortization period for certain callable debt securities held at a premium. The standard requires the premium of qualifying debt securities to be amortized to the earliest call date. The update does not change the accounting for callable debt securities held at a discount. January 1, 2019 We adopted this standard at the beginning of the current quarter using a modified retrospective transition approach. As a result of adoption, we recorded a $3 million decrease to retained earnings on January 1, 2019, as a cumulative effect adjustment. ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement The purpose of this ASU is to improve the effectiveness of disclosures in the notes to the financial statements. This Update removes, modifies, and makes certain additions to the disclosure requirements for fair value measurement. The mandatory adoption date of the guidance in this ASU is for the first fiscal period beginning after December 15, 2019, with early adoption permitted. January 1, 2019 We early adopted this ASU in the current quarter. This standard will be applied prospectively. The changes to the disclosure requirements for fair value measurements are immaterial to the financial statements and can be found in Note 3. ASU 2018-15, Intangibles – Goodwill and Other-Internal- Use Software (Topic 350-40): Customer’s Accounting for Implementation Cost Incurred in a Cloud Computing Arrangement That Is a Service Contract This ASU aligns the requirements for capitalizing implementation costs associated with Cloud Computing Arrangements that meet the definition of a service contract with requirements already provided for costs associated with internal-use software. Additionally, it clarifies that: -The amortization period for capitalized amounts will be the noncancelable hosting contract term plus any expected renewal periods. -Entities in a hosting arrangement that is a service contract must provide certain qualitative and quantitative disclosures. -Transition for those not already following the provisions of this ASU can be applied either retrospectively or prospectively. January 1, 2019 We early adopted this ASU in the current quarter. The Bank has historically been applying the guidance as clarified in this ASU. Consequently, the adoption of the ASU did not have a material impact on the Bank’s financial statements.

Fair Value

Fair Value	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value	FAIR VALUE Fair Value Measurement Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. For a discussion of the Bank’s valuation methodologies for assets and liabilities measured at fair value and the fair value hierarchy, see Note 3 of our 2018 Annual Report on Form 10-K. Quantitative Disclosure by Fair Value Hierarchy Assets and liabilities measured at fair value by class on a recurring basis are summarized as follows: (In millions) March 31, 2019 Level 1 Level 2 Level 3 Total ASSETS Investment securities: Available-for-sale: 1 U.S. Treasury, agencies and corporations $ 40 $ 13,559 $ — $ 13,599 Municipal securities 1,283 1,283 Other debt securities 22 22 Total Available-for-sale 40 14,864 — 14,904 Trading account 161 155 316 Other noninterest-bearing investments: Bank-owned life insurance 518 518 Private equity investments 107 107 Other assets: Agriculture loan servicing and interest-only strips 17 17 Deferred compensation plan assets 107 107 Derivatives: Derivatives designated as hedges 9 9 Derivatives not designated as hedges: Customer-facing interest rate 69 69 Other interest rate 1 1 Foreign exchange 3 3 Total Assets $ 311 $ 15,616 $ 124 $ 16,051 LIABILITIES Securities sold, not yet purchased $ 52 $ — $ — $ 52 Other liabilities: Deferred compensation plan obligations 107 107 Derivatives: Derivatives not designated as hedges: Customer-facing interest rate 22 22 Other interest rate 1 1 Foreign exchange 2 2 Total Liabilities $ 161 $ 23 $ — $ 184 1 We used a third-party pricing service to measure fair value for approximately 94% of our AFS Level 2 securities. (In millions) December 31, 2018 Level 1 Level 2 Level 3 Total ASSETS Investment securities: Available-for-sale: 1 U.S. Treasury, agencies and corporations $ 40 $ 13,385 $ — $ 13,425 Municipal securities 1,291 1,291 Other debt securities 21 21 Total Available-for-sale 40 14,697 — 14,737 Trading account 14 92 106 Other noninterest-bearing investments: Bank-owned life insurance 516 516 Private equity investments 102 102 Other assets: Agriculture loan servicing and interest-only strips 18 18 Deferred compensation plan assets 95 95 Derivatives: Derivatives not designated as hedges: Customer-facing interest rate 40 40 Other interest rate 1 1 Foreign exchange 4 4 Total Assets $ 153 $ 15,346 $ 120 $ 15,619 LIABILITIES Securities sold, not yet purchased $ 85 $ — $ — $ 85 Other liabilities: Deferred compensation plan obligations 95 95 Derivatives: Derivatives not designated as hedges: Customer-facing interest rate 36 36 Other interest rate 1 1 Foreign exchange 2 2 Total Liabilities $ 182 $ 37 $ — $ 219 1 We used a third-party pricing service to measure fair value for approximately 95% of our AFS Level 2 securities. Level 3 Valuations The Bank’s Level 3 holdings include private equity investments (“PEIs”), agriculture loan servicing, and interest-only strips. For additional information regarding the financial instruments measured under Level 3, and the methods and significant assumptions used to estimate their fair value, see Note 3 of our 2018 Annual Report on Form 10-K. Reconciliation of Level 3 Fair Value Measurements The following reconciles the beginning and ending balances of assets and liabilities that are measured at fair value by class on a recurring basis using Level 3 inputs: Level 3 Instruments Three Months Ended March 31, 2019 March 31, 2018 (In millions) Private Ag loan svcg and int-only strips Private Ag loan svcg and int-only strips Balance at beginning of period $ 102 $ 18 $ 95 $ 18 Securities gains (losses), net 1 — — — Other noninterest income — (1 ) — — Purchases 4 — 5 — Balance at end of period $ 107 $ 17 $ 100 $ 18 The reconciliation of Level 3 instruments does not include any realized gains and losses in the statement of income during the three months ended March 31 , 2019 and 2018 . Nonrecurring Fair Value Measurements Included in the balance sheet amounts are the following amounts of assets that had fair value changes measured on a nonrecurring basis. (In millions) Fair value at March 31, 2019 Fair value at December 31, 2018 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total ASSETS Private equity investments $ — $ — $ — $ — $ — $ — $ 1 $ 1 Impaired loans — 2 — 2 — 32 — 32 Other real estate owned — 1 — 1 — — — — Total $ — $ 3 $ — $ 3 $ — $ 32 $ 1 $ 33 The previous fair values may not be current as of the dates indicated, but rather as of the date the fair value change occurred, such as a charge for impairment. Accordingly, carrying values may not equal current fair value. Gains (losses) from fair value changes (In millions) Three Months Ended 2019 2018 ASSETS Private equity investments $ — $ — Impaired loans (4 ) (4 ) Other real estate owned — (1 ) Total $ (4 ) $ (5 ) During the three months ended March 31 , we recognized less than $1 million of net gains in 2019 and 2018 from the sale of OREO properties that had a carrying value, at the time of sale, of approximately $1 million during these same periods. Prior to their sale, we recognized an insignificant amount of impairment on these properties during the three months ended March 31 , 2019 and 2018 . Private equity investments carried at cost were measured at fair value for impairment purposes according to the methodology previously discussed for these investments. Amounts of PEIs carried at cost were $10 million at March 31, 2019 and December 31, 2018 . Amounts of other noninterest-bearing investments carried at cost were $272 million at March 31, 2019 and $329 million at December 31, 2018 , which were comprised of Federal Reserve and Federal Home Loan Bank (“FHLB”) stock. Private equity investments accounted for using the equity method were $36 million at March 31, 2019 and $35 million at December 31, 2018 . Impaired (or nonperforming) loans that are collateral-dependent were measured at fair value based on the fair value of the collateral. OREO was measured initially at fair value based on collateral appraisals at the time of transfer and subsequently at the lower of cost or fair value. For additional information regarding the measurement of fair value for impaired loans, collateral-dependent loans, and OREO, see Note 3 of our 2018 Annual Report on Form 10-K. Fair Value of Certain Financial Instruments Following is a summary of the carrying values and estimated fair values of certain financial instruments: March 31, 2019 December 31, 2018 (In millions) Carrying value Estimated fair value Level Carrying value Estimated fair value Level Financial assets: HTM investment securities $ 764 $ 762 2 $ 774 $ 767 2 Loans and leases (including loans held for sale), net of allowance 47,178 46,197 3 46,312 45,251 3 Financial liabilities: Time deposits 4,928 4,921 2 4,336 4,319 2 Long-term debt 1,228 1,240 2 724 727 2 This summary excludes financial assets and liabilities for which carrying value approximates fair value and financial instruments that are recorded at fair value on a recurring basis. For additional information regarding the financial instruments within the scope of this disclosure, and the methods and significant assumptions used to estimate their fair value, see Note 3 of our 2018 Annual Report on Form 10-K.

Offsetting Assets and Liabiliti

Offsetting Assets and Liabilities (Notes)	3 Months Ended
	Mar. 31, 2019
Offsetting Assets and Liabilities [Abstract]
Cash, Cash Equivalents, and Short-term Investments [Text Block]	OFFSETTING ASSETS AND LIABILITIES Gross and net information for selected financial instruments in the balance sheet is as follows: March 31, 2019 (In millions) Gross amounts not offset in the balance sheet Description Gross amounts recognized Gross amounts offset in the balance sheet Net amounts presented in the balance sheet Financial instruments Cash collateral received/pledged Net amount Assets: Federal funds sold and security resell agreements $ 739 $ (301 ) $ 438 $ — $ — $ 438 Derivatives (included in other assets) 82 — 82 (21 ) (5 ) 56 Total assets $ 821 $ (301 ) $ 520 $ (21 ) $ (5 ) $ 494 Liabilities: Federal funds and other short-term borrowings $ 5,245 $ (301 ) $ 4,944 $ — $ — $ 4,944 Derivatives (included in other liabilities) 25 — 25 (21 ) — 4 Total Liabilities $ 5,270 $ (301 ) $ 4,969 $ (21 ) $ — $ 4,948 December 31, 2018 (In millions) Gross amounts not offset in the balance sheet Description Gross amounts recognized Gross amounts offset in the balance sheet Net amounts presented in the balance sheet Financial instruments Cash collateral received/pledged Net amount Assets: Federal funds sold and security resell agreements $ 1,461 $ — $ 1,461 $ — $ — $ 1,461 Derivatives (included in other assets) 45 — 45 (35 ) (3 ) 7 Total assets $ 1506 $ — $ 1506 $ (35 ) $ (3 ) $ 1468 Liabilities: Federal funds and other short-term borrowings $ 5,653 $ — $ 5,653 $ — $ — $ 5,653 Derivatives (included in other liabilities) 39 — 39 (35 ) (1 ) 3 Total Liabilities $ 5,692 $ — $ 5,692 $ (35 ) $ (1 ) $ 5,656 Security repurchase and reverse repurchase (“resell”) agreements are offset, when applicable, in the balance sheet according to master netting agreements. Security repurchase agreements are included with “Federal funds and other short-term borrowings.” Derivative instruments may be offset under their master netting agreements; however, for accounting purposes, we present these items on a gross basis in the Bank’s balance sheet. See Note 7 for further information regarding derivative instruments.

Investment Securities

Investment Securities	3 Months Ended
	Mar. 31, 2019
Investments [Abstract]
Investment Securities	INVESTMENTS Investment Securities Securities are classified as HTM, AFS or trading. HTM securities, which management has the intent and ability to hold until maturity, are carried at amortized cost. AFS securities are carried at fair value and unrealized gains and losses, after applicable taxes, are recorded as net increases or decreases to accumulated other comprehensive income (“AOCI”). Realized gains and losses on AFS securities are determined by using the cost basis of each individual security. Trading securities are carried at fair value with gains and losses recognized in current period earnings. The purchase premiums for callable debt securities classified as HTM or AFS are amortized at a constant effective yield to the earliest call date. The purchase premiums and discounts for all other HTM and AFS securities are amortized and accreted at a constant effective yield to the contractual maturity date and no assumption is made concerning prepayments. As principal prepayments occur, the portion of the unamortized premium or discount associated with the principal reduction is recognized in interest income in the period the principal is reduced. Note 3 of our 2018 Annual Report on Form 10-K discusses the process to estimate fair value for investment securities. March 31, 2019 (In millions) Amortized cost Gross unrealized gains Gross unrealized losses Estimated fair value Held-to-maturity Municipal securities $ 764 $ 4 $ 6 $ 762 Available-for-sale U.S. Treasury securities 40 — — 40 U.S. Government agencies and corporations: Agency securities 1,407 2 11 1,398 Agency guaranteed mortgage-backed securities 10,384 36 136 10,284 Small Business Administration loan-backed securities 1,919 1 43 1,877 Municipal securities 1,270 16 3 1,283 Other debt securities 25 — 3 22 Total available-for-sale 15,045 55 196 14,904 Total investment securities $ 15,809 $ 59 $ 202 $ 15,666 December 31, 2018 (In millions) Amortized Gross unrealized gains Gross unrealized losses Estimated Held-to-maturity Municipal securities $ 774 $ 4 $ 11 $ 767 Available-for-sale U.S. Treasury securities 40 — — 40 U.S. Government agencies and corporations: Agency securities 1,394 — 19 1,375 Agency guaranteed mortgage-backed securities 10,236 18 240 10,014 Small Business Administration loan-backed securities 2,042 1 47 1,996 Municipal securities 1,303 4 16 1,291 Other debt securities 25 — 4 21 Total available-for-sale debt securities 15,040 23 326 14,737 Total investment securities $ 15,814 $ 27 $ 337 $ 15,504 Maturities The amortized cost and estimated fair value of investment debt securities are shown subsequently as of March 31, 2019 , by expected timing of principal payments. Actual principal payments may differ from contractual or expected principal payments because borrowers may have the right to call or prepay obligations with or without call or prepayment penalties. March 31, 2019 Held-to-maturity Available-for-sale (In millions) Amortized cost Estimated fair value Amortized cost Estimated fair value Due in one year or less $ 252 $ 252 $ 2,147 $ 2,125 Due after one year through five years 329 328 5,984 5,928 Due after five years through ten years 132 132 4,441 4,406 Due after ten years 51 50 2,473 2,445 Total debt investment securities $ 764 $ 762 $ 15,045 $ 14,904 The following is a summary of the amount of gross unrealized losses for debt securities and the estimated fair value by length of time the securities have been in an unrealized loss position: March 31, 2019 Less than 12 months 12 months or more Total (In millions) Gross unrealized losses Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses Estimated fair value Held-to-maturity Municipal securities $ — $ 24 $ 6 $ 415 $ 6 $ 439 Available-for-sale U.S. Government agencies and corporations: Agency securities — 46 11 994 11 1,040 Agency guaranteed mortgage-backed securities 2 270 134 6,799 136 7,069 Small Business Administration loan-backed securities 13 876 30 898 43 1,774 Municipal securities — 40 3 458 3 498 Other — — 3 12 3 12 Total available-for-sale 15 1,232 181 9,161 196 10,393 Total investment securities $ 15 $ 1,256 $ 187 $ 9,576 $ 202 $ 10,832 December 31, 2018 Less than 12 months 12 months or more Total (In millions) Gross unrealized losses Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses Estimated fair value Held-to-maturity Municipal securities $ 1 $ 86 $ 10 $ 438 $ 11 $ 524 Available-for-sale U.S. Government agencies and corporations: Agency securities 2 245 17 913 19 1,158 Agency guaranteed mortgage-backed securities 16 1,081 224 6,661 240 7,742 Small Business Administration loan-backed securities 19 1,180 28 711 47 1,891 Municipal securities 2 266 14 641 16 907 Other — — 4 11 4 11 Total available-for-sale 39 2,772 287 8,937 326 11,709 Total investment securities $ 40 $ 2,858 $ 297 $ 9,375 $ 337 $ 12,233 At March 31, 2019 and December 31, 2018 , respectively, 464 and 606 HTM and 1,891 and 2,588 AFS investment securities were in an unrealized loss position. Other-Than-Temporary Impairment The Bank did not recognize any OTTI on its investment securities portfolio during the first three months of 2019 . We review investment securities on a quarterly basis for the presence of OTTI. Unrealized losses relate to changes in interest rates subsequent to purchase and are not attributable to credit. At March 31, 2019 , we did not have an intent to sell identified securities with unrealized losses or initiate such sales, and we believe it is not more likely than not we would be required to sell such securities before recovery of their amortized cost basis. For additional information on our policy and evaluation process relating to OTTI, see Note 5 of our 2018 Annual Report on Form 10-K. The following summarizes gains and losses that were recognized in the statement of income: Three Months Ended March 31, 2019 2018 (In millions) Gross gains Gross losses Gross gains Gross losses Investment securities: Other noninterest-bearing investments $ 4 $ 3 $ 1 $ 1 Net gains 1 $ 1 $ — 1 Net gains were recognized in securities gains (losses), net in the statement of income. Interest income by security type is as follows: Three Months Ended March 31, (In millions) 2019 2018 Taxable Nontaxable Total Taxable Nontaxable Total Investment securities: Held-to-maturity $ 2 $ 4 $ 6 $ 2 $ 4 $ 6 Available-for-sale 83 6 89 73 6 79 Trading — 1 1 — 1 1 Total securities $ 85 $ 11 $ 96 $ 75 $ 11 $ 86 Investment securities with a carrying value of $3.1 billion at March 31, 2019 and $2.6 billion at December 31, 2018 , respectively, were pledged to secure public and trust deposits, advances, and for other purposes as required by law. Securities are also pledged as collateral for security repurchase agreements.

Loans And Allowance For Credit

Loans And Allowance For Credit Losses	3 Months Ended
	Mar. 31, 2019
Loans And Allowance For Credit Losses [Abstract]
Loans And Allowance For Credit Losses	LOANS AND ALLOWANCE FOR CREDIT LOSSES Loans and Loans Held for Sale Loans are summarized as follows according to major portfolio segment and specific loan class: (In millions) March 31, December 31, Loans held for sale $ 69 $ 93 Commercial: Commercial and industrial $ 14,758 $ 14,513 Leasing 312 327 Owner-occupied 7,754 7,661 Municipal 1,774 1,661 Total commercial 24,598 24,162 Commercial real estate: Construction and land development 2,343 2,186 Term 9,187 8,939 Total commercial real estate 11,530 11,125 Consumer: Home equity credit line 2,884 2,937 1-4 family residential 7,294 7,176 Construction and other consumer real estate 636 643 Bankcard and other revolving plans 489 491 Other 175 180 Total consumer 11,478 11,427 Total loans 1 $ 47,606 $ 46,714 1 Loans are presented net of unearned income, unamortized purchase premiums and discounts, and net deferred loan fees and costs totaling $51 million and $50 million at March 31, 2019 and December 31, 2018 , respectively. Municipal loans generally include loans to state and local governments (“municipalities”) with the debt service being repaid from general funds or pledged revenues of the municipal entity, or to private commercial entities or 501(c)(3) not-for-profit entities utilizing a pass-through municipal entity to achieve favorable tax treatment. Land acquisition and development loans included in the construction and land development loan portfolio were $231 million at March 31, 2019 and $237 million at December 31, 2018 . Loans with a carrying value of approximately $23.4 billion at March 31, 2019 and $22.6 billion at December 31, 2018 have been pledged at the Federal Reserve or the FHLB of Des Moines as collateral for current and potential borrowings. We sold loans totaling $118 million and $106 million for the three months ended March 31, 2019 and 2018, respectively, that were classified as loans held for sale. The sold loans were derecognized from the balance sheet. Loans classified as loans held for sale primarily consist of conforming residential mortgages and the guaranteed portion of Small Business Administration (“SBA”) loans. The loans are mainly sold to U.S. government agencies or participated to third parties. At times, we have continuing involvement in the transferred loans in the form of servicing rights or a guarantee from the respective issuer. Amounts added to loans held for sale during these same periods was $93 million and $165 million , respectively. See Note 5 for further information regarding guaranteed securities. The principal balance of sold loans for which we retain servicing was approximately $2.2 billion at both March 31, 2019 and December 31, 2018 . Income from loans sold, excluding servicing, was $2 million and $3 million for the three months ended March 31, 2019 and 2018, respectively. Allowance for Credit Losses The allowance for credit losses (“ACL”) consists of the allowance for loan and lease losses (“ALLL”) and the reserve for unfunded lending commitments (“RULC”). The ALLL represents our estimate of probable and estimable losses inherent in the loan and lease portfolio as of the balance sheet date. We also estimate a reserve for potential losses associated with off-balance sheet commitments, including standby letters of credit. We determine the RULC using the same procedures and methodologies that we use for the ALLL. For additional information regarding our policies and methodologies used to estimate the ACL, see Note 6 of our 2018 Annual Report on Form 10-K. Changes in the allowance for credit losses are summarized as follows: Three Months Ended March 31, 2019 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses Balance at beginning of period $ 331 $ 110 $ 54 $ 495 Provision for loan losses (1 ) 1 2 2 Deductions: Gross loan and lease charge-offs 8 1 3 12 Recoveries 6 3 3 12 Net loan and lease charge-offs (recoveries) 2 (2 ) — — Balance at end of period $ 328 $ 113 $ 56 $ 497 Reserve for unfunded lending commitments Balance at beginning of period $ 40 $ 17 $ — $ 57 Provision for unfunded lending commitments 2 — — 2 Balance at end of period $ 42 $ 17 $ — $ 59 Total allowance for credit losses at end of period Allowance for loan losses $ 328 $ 113 $ 56 $ 497 Reserve for unfunded lending commitments 42 17 — 59 Total allowance for credit losses $ 370 $ 130 $ 56 $ 556 Three Months Ended March 31, 2018 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses Balance at beginning of period $ 371 $ 103 $ 44 $ 518 Provision for loan losses (40 ) (1 ) 1 (40 ) Gross loan and lease charge-offs 20 — 6 26 Recoveries 18 2 1 21 Net loan and lease charge-offs (recoveries) 2 (2 ) 5 5 Balance at end of period $ 329 $ 104 $ 40 $ 473 Reserve for unfunded lending commitments Balance at beginning of period $ 48 $ 10 $ — $ 58 Provision for unfunded lending commitments (8 ) 1 — (7 ) Balance at end of period $ 40 $ 11 $ — $ 51 Total allowance for credit losses at end of period Allowance for loan losses $ 329 $ 104 $ 40 $ 473 Reserve for unfunded lending commitments 40 11 — 51 Total allowance for credit losses $ 369 $ 115 $ 40 $ 524 The ALLL and outstanding loan balances according to the Bank’s impairment method are summarized as follows: March 31, 2019 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses: Individually evaluated for impairment $ 6 $ 1 $ 2 $ 9 Collectively evaluated for impairment 322 112 54 488 Total $ 328 $ 113 $ 56 $ 497 Outstanding loan balances: Individually evaluated for impairment $ 148 $ 50 $ 70 $ 268 Collectively evaluated for impairment 24,450 11,480 11,408 47,338 Total $ 24,598 $ 11,530 $ 11,478 $ 47,606 December 31, 2018 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses: Individually evaluated for impairment $ 6 $ 1 $ 2 $ 9 Collectively evaluated for impairment 325 109 52 486 Total $ 331 $ 110 $ 54 $ 495 Outstanding loan balances: Individually evaluated for impairment $ 164 $ 55 $ 72 $ 291 Collectively evaluated for impairment 23,998 11,070 11,355 46,423 Total $ 24,162 $ 11,125 $ 11,427 $ 46,714 Nonaccrual and Past Due Loans Loans are generally placed on nonaccrual status when payment in full of principal and interest is not expected, or the loan is 90 days or more past due as to principal or interest, unless the loan is both well secured and in the process of collection. For further discussion of our policies and processes regarding nonaccrual and past due loans, see Note 6 of our 2018 Annual Report on Form 10-K. Nonaccrual loans are summarized as follows: (In millions) March 31, December 31, Loans held for sale $ — $ 6 Commercial: Commercial and industrial $ 72 $ 82 Leasing 1 2 Owner-occupied 69 67 Municipal 1 1 Total commercial 143 152 Commercial real estate: Construction and land development 1 — Term 32 38 Total commercial real estate 33 38 Consumer: Home equity credit line 11 13 1-4 family residential 45 42 Construction and other consumer real estate 2 — Bankcard and other revolving plans — 1 Other — — Total consumer loans 58 56 Total $ 234 $ 246 Past due loans (accruing and nonaccruing) are summarized as follows: March 31, 2019 (In millions) Current 30-89 days past due 90+ days past due Total past due Total loans Accruing loans 90+ days past due Nonaccrual loans that are current 1 Loans held for sale $ 69 $ — $ — $ — $ 69 $ — $ — Commercial: Commercial and industrial $ 14,646 $ 86 $ 26 $ 112 $ 14,758 $ 4 $ 43 Leasing 311 — 1 1 312 — 1 Owner-occupied 7,702 33 19 52 7,754 1 45 Municipal 1,774 — — — 1,774 — 1 Total commercial 24,433 119 46 165 24,598 5 90 Commercial real estate: Construction and land development 2,333 9 1 10 2,343 1 — Term 9,164 17 6 23 9,187 1 24 Total commercial real estate 11,497 26 7 33 11,530 2 24 Consumer: Home equity credit line 2,875 5 4 9 2,884 — 5 1-4 family residential 7,260 13 21 34 7,294 — 17 Construction and other consumer real estate 636 — — — 636 — 2 Bankcard and other revolving plans 485 3 1 4 489 1 — Other 174 1 — 1 175 — — Total consumer loans 11,430 22 26 48 11,478 1 24 Total $ 47,360 $ 167 $ 79 $ 246 $ 47,606 $ 8 $ 138 December 31, 2018 (In millions) Current 30-89 days past due 90+ days past due Total past due Total loans Accruing loans 90+ days past due Nonaccrual loans that are current 1 Loans held for sale $ 89 $ — $ 4 $ 4 $ 93 $ — $ 2 Commercial: Commercial and industrial $ 14,445 $ 37 $ 31 $ 68 $ 14,513 $ 4 $ 46 Leasing 325 1 1 2 327 — 1 Owner-occupied 7,621 23 17 40 7,661 3 48 Municipal 1,661 — — — 1,661 — 1 Total commercial 24,052 61 49 110 24,162 7 96 Commercial real estate: Construction and land development 2,185 1 — 1 2,186 — — Term 8,924 4 11 15 8,939 1 26 Total commercial real estate 11,109 5 11 16 11,125 1 26 Consumer: Home equity credit line 2,927 4 6 10 2,937 — 4 1-4 family residential 7,143 15 18 33 7,176 — 19 Construction and other consumer real estate 642 1 — 1 643 — — Bankcard and other revolving plans 487 2 2 4 491 2 — Other 179 1 — 1 180 — — Total consumer loans 11,378 23 26 49 11,427 2 23 Total $ 46,539 $ 89 $ 86 $ 175 $ 46,714 $ 10 $ 145 1 Represents nonaccrual loans that are not past due more than 30 days; however, full payment of principal and interest is still not expected. Credit Quality Indicators In addition to the past due and nonaccrual criteria, we also analyze loans using loan risk-grading systems, which vary based on the size and type of credit risk exposure. The internal risk grades assigned to loans follow our definitions of Pass, Special Mention, Sub-standard, and Doubtful, which are consistent with published definitions of regulatory risk classifications. For further discussion of our policies and processes regarding credit quality indicators and internal loan risk-grading, see Note 6 of our 2018 Annual Report on Form 10-K. Outstanding loan balances (accruing and nonaccruing) categorized by these credit quality classifications are summarized as follows: March 31, 2019 (In millions) Pass Special Mention Sub- standard Doubtful Total loans Total allowance Commercial: Commercial and industrial $ 14,047 $ 389 $ 322 $ — $ 14,758 Leasing 299 10 3 — 312 Owner-occupied 7,448 82 224 — 7,754 Municipal 1,745 2 27 — 1,774 Total commercial 23,539 483 576 — 24,598 $ 328 Commercial real estate: Construction and land development 2,334 — 9 — 2,343 Term 9,080 34 73 — 9,187 Total commercial real estate 11,414 34 82 — 11,530 113 Consumer: Home equity credit line 2,868 — 16 — 2,884 1-4 family residential 7,245 — 49 — 7,294 Construction and other consumer real estate 633 — 3 — 636 Bankcard and other revolving plans 487 — 2 — 489 Other 174 — 1 — 175 Total consumer loans 11,407 — 71 — 11,478 56 Total $ 46,360 $ 517 $ 729 $ — $ 47,606 $ 497 December 31, 2018 (In millions) Pass Special Mention Sub- standard Doubtful Total loans Total allowance Commercial: Commercial and industrial $ 13,891 $ 322 $ 300 $ — $ 14,513 Leasing 313 10 4 — 327 Owner-occupied 7,369 72 220 — 7,661 Municipal 1,632 2 27 — 1,661 Total commercial 23,205 406 551 — 24,162 $ 331 Commercial real estate: Construction and land development 2,174 11 1 — 2,186 Term 8,853 10 76 — 8,939 Total commercial real estate 11,027 21 77 — 11,125 110 Consumer: Home equity credit line 2,920 — 17 — 2,937 1-4 family residential 7,129 — 47 — 7,176 Construction and other consumer real estate 641 — 2 — 643 Bankcard and other revolving plans 488 — 3 — 491 Other 179 — 1 — 180 Total consumer loans 11,357 — 70 — 11,427 54 Total $ 45,589 $ 427 $ 698 $ — $ 46,714 $ 495 Impaired Loans Loans are considered impaired when, based on current information and events, it is probable that we will be unable to collect all amounts due in accordance with the contractual terms of the loan agreement, including scheduled interest payments. Payments received on impaired loans that are accruing are recognized in interest income, according to the contractual loan agreement. Payments received on impaired loans that are on nonaccrual are not recognized in interest income, but are applied as a reduction to the principal outstanding. The amount of interest income recognized on a cash basis during the time the loans were impaired within the three months ended March 31, 2019 and 2018 was not significant. For additional information regarding our policies and methodologies used to evaluate impaired loans, see Note 6 of our 2018 Annual Report on Form 10-K. Information on impaired loans individually evaluated is summarized as follows, including the average recorded investment and interest income recognized for the three months ended March 31, 2019 and 2018 : March 31, 2019 (In millions) Unpaid principal balance Recorded investment Total recorded investment Related allowance with no allowance with allowance Commercial: Commercial and industrial $ 99 $ 35 $ 44 $ 79 $ 5 Owner-occupied 56 42 11 53 1 Municipal 1 1 — 1 — Total commercial 156 78 55 133 6 Commercial real estate: Construction and land development — — — — — Term 39 33 2 35 — Total commercial real estate 39 33 2 35 — Consumer: Home equity credit line 15 12 3 15 — 1-4 family residential 63 30 23 53 2 Construction and other consumer real estate 2 — 2 2 — Other — — — — — Total consumer loans 80 42 28 70 2 Total $ 275 $ 153 $ 85 $ 238 $ 8 December 31, 2018 (In millions) Unpaid principal balance Recorded investment Total recorded investment Related allowance with no allowance with allowance Commercial: Commercial and industrial $ 112 $ 52 $ 36 $ 88 $ 4 Owner-occupied 67 31 29 60 2 Municipal 1 1 — 1 — Total commercial 180 84 65 149 6 Commercial real estate: Construction and land development 1 — — — — Term 44 37 3 40 — Total commercial real estate 45 37 3 40 — Consumer: Home equity credit line 15 12 2 14 — 1-4 family residential 69 32 25 57 2 Construction and other consumer real estate 1 1 — 1 — Other — — — — — Total consumer loans 85 45 27 72 2 Total $ 310 $ 166 $ 95 $ 261 $ 8 Three Months Ended Three Months Ended (In millions) Average recorded investment Interest income recognized Average recorded investment Interest income recognized Commercial: Commercial and industrial $ 83 $ 1 $ 148 $ — Owner-occupied 60 — 91 8 Municipal 1 — 1 — Total commercial 144 1 240 8 Commercial real estate: Construction and land development — — 5 — Term 35 — 57 — Total commercial real estate 35 — 62 — Consumer: Home equity credit line 14 — 20 — 1-4 family residential 55 — 55 — Construction and other consumer real estate 2 — 2 — Other — — — — Total consumer loans 71 — 77 — Total $ 250 $ 1 $ 379 $ 8 Modified and Restructured Loans Loans may be modified in the normal course of business for competitive reasons or to strengthen the Bank’s position. Loan modifications and restructurings may also occur when the borrower experiences financial difficulty and needs temporary or permanent relief from the original contractual terms of the loan. Loans that have been modified to accommodate a borrower who is experiencing financial difficulties, and for which the Bank has granted a concession that it would not otherwise consider, are considered troubled debt restructurings (“TDRs”). For further discussion of our policies and processes regarding TDRs, see Note 6 of our 2018 Annual Report on Form 10-K. Selected information on TDRs that includes the recorded investment on an accruing and nonaccruing basis by loan class and modification type is summarized in the following schedules: March 31, 2019 Recorded investment resulting from the following modification types: (In millions) Interest rate below market Maturity or term extension Principal forgiveness Payment deferral Other 1 Multiple modification types 2 Total Accruing Commercial: Commercial and industrial $ 2 $ 4 $ — $ — $ 14 $ 6 $ 26 Owner-occupied 4 1 — — 3 7 15 Municipal — — — — — — — Total commercial 6 5 — — 17 13 41 Commercial real estate: Construction and land development — — — — — — — Term 1 2 — 1 — 5 9 Total commercial real estate 1 2 — 1 — 5 9 Consumer: Home equity credit line — 1 9 — — 2 12 1-4 family residential 1 1 6 1 1 25 35 Construction and other consumer real estate — 1 — — — — 1 Total consumer loans 1 3 15 1 1 27 48 Total accruing 8 10 15 2 18 45 98 Nonaccruing Commercial: Commercial and industrial 1 4 — 1 2 24 32 Owner-occupied 6 — — — 1 6 13 Municipal — — — — — 1 1 Total commercial 7 4 — 1 3 31 46 Commercial real estate: Term 3 — — 2 3 12 20 Total commercial real estate 3 — — 2 3 12 20 Consumer: Home equity credit line — — 1 — — — 1 1-4 family residential — — 1 — 1 7 9 Total consumer loans — — 2 — 1 7 10 Total nonaccruing 10 4 2 3 7 50 76 Total $ 18 $ 14 $ 17 $ 5 $ 25 $ 95 $ 174 1 Includes TDRs that resulted from other modification types including, but not limited to, a legal judgment awarded on different terms, a bankruptcy plan confirmed on different terms, a settlement that includes the delivery of collateral in exchange for debt reduction, etc. 2 Includes TDRs that resulted from a combination of any of the previous modification types. December 31, 2018 Recorded investment resulting from the following modification types: (In millions) Interest rate below market Maturity or term extension Principal forgiveness Payment deferral Other 1 Multiple modification types 2 Total Accruing Commercial: Commercial and industrial $ 2 $ 4 $ — $ — $ 15 $ 7 $ 28 Owner-occupied 3 2 — — 2 14 21 Total commercial 5 6 — — 17 21 49 Commercial real estate: Construction and land development — — — — — — — Term 2 2 — 1 — 6 11 Total commercial real estate 2 2 — 1 — 6 11 Consumer: Home equity credit line — 1 8 — — 3 12 1-4 family residential 1 2 6 1 1 28 39 Construction and other consumer real estate — — — — — 1 1 Total consumer loans 1 3 14 1 1 32 52 Total accruing 8 11 14 2 18 59 112 Nonaccruing Commercial: Commercial and industrial 1 6 — 1 10 27 45 Owner-occupied 6 — — 1 2 5 14 Municipal — — — — — 1 1 Total commercial 7 6 — 2 12 33 60 Commercial real estate: Term 3 — — 2 14 1 20 Total commercial real estate 3 — — 2 14 1 20 Consumer: Home equity credit line — — 1 — — — 1 1-4 family residential — — 1 — 1 7 9 Total consumer loans — — 2 — 1 7 10 Total nonaccruing 10 6 2 4 27 41 90 Total $ 18 $ 17 $ 16 $ 6 $ 45 $ 100 $ 202 1 Includes TDRs that resulted from other modification types including, but not limited to, a legal judgment awarded on different terms, a bankruptcy plan confirmed on different terms, a settlement that includes the delivery of collateral in exchange for debt reduction, etc. 2 Includes TDRs that resulted from a combination of any of the previous modification types. Unfunded lending commitments on TDRs amounted to approximately $11 million at both March 31, 2019 and December 31, 2018 . The total recorded investment of all TDRs in which interest rates were modified below market was $80 million at March 31, 2019 and $88 million at December 31, 2018 . These loans are included in the previous schedule in the columns for interest rate below market and multiple modification types. The net financial impact on interest income due to interest rate modifications below market for accruing TDRs for the three months ended March 31, 2019 and 2018 was not significant. On an ongoing basis, we monitor the performance of all TDRs according to their restructured terms. Subsequent payment default is defined in terms of delinquency, when principal or interest payments are past due 90 days or more for commercial loans, or 60 days or more for consumer loans. The recorded investment of accruing and nonaccruing TDRs that had a payment default during the period listed below (and are still in default at period end) and are within 12 months or less of being modified as TDRs is as follows: Three Months Ended Three Months Ended (In millions) Accruing Nonaccruing Total Accruing Nonaccruing Total Commercial: Commercial and industrial $ — $ 3 $ 3 $ — $ 1 $ 1 Owner-occupied — — — — 1 1 Total commercial — 3 3 — 2 2 Commercial real estate: Term — 2 2 — — — Total commercial real estate — 2 2 — — — Total $ — $ 5 $ 5 $ — $ 2 $ 2 Note: Total loans modified as TDRs during the 12 months previous to March 31, 2019 and 2018 were $73 million and $111 million , respectively. At March 31, 2019 and December 31, 2018 , the amount of foreclosed residential real estate property held by the Bank was approximately $1 million and $2 million , and the recorded investment in consumer mortgage loans collateralized by residential real estate property that are in the process of foreclosure was approximately $9 million and $10 million , respectively. Concentrations of Credit Risk Credit risk is the possibility of loss from the failure of a borrower, guarantor, or another obligor to fully perform under the terms of a credit-related contract. We perform an ongoing analysis of our loan portfolio to evaluate whether there is any significant exposure to any concentrations of credit risk. See Note 6 of our 2018 Annual Report on Form 10-K for further discussion of our evaluation of credit risk concentrations. See also Note 7 of our 2018 Annual Report on Form 10-K for a discussion of counterparty risk associated with the Bank’s derivative transactions.

Derivative Instruments And Hedg

Derivative Instruments And Hedging Activities	3 Months Ended
	Mar. 31, 2019
Summary of Derivative Instruments [Abstract]
Derivative Instruments And Hedging Activities	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES Objectives and Accounting The Bank is exposed to certain risks arising from both its business operations and economic conditions. Our objectives in using derivatives are to add stability to interest income or expense, to modify the duration of specific assets or liabilities as we consider advisable, to manage exposure to interest rate movements or other identified risks, and/or to directly offset derivatives sold to our customers. For a detailed discussion of the use of and accounting policies regarding derivative instruments, see Note 7 of our 2018 Annual Report on Form 10-K. Fair Value Hedges – As of March 31, 2019 , the Bank had designated $1 billion of interest rate swaps in two separate qualifying fair value hedge relationships. Each hedge has a notional amount of $500 million , with the first $500 million maturing in August of 2021 and the second $500 million maturing in February of 2022. The hedging instruments used are receive-fixed interest rate swaps designated as hedges of the change in fair value of the London Interbank Offered Rate (“LIBOR”) benchmark swap rate component of the contractual coupon cash flows of these notes. Both swaps are structured to match the critical terms of the hedged notes, resulting in the expectation that the swaps will be highly effective as hedging instruments. The first swap has a rate of 3.50% , while the second swap, which was added during the first quarter of 2019, has a receive-fixed rate of 3.35% , making the average received-fixed strike rate 3.43% for all existing fair value hedges designated at the balance sheet date. The Bank fully amortized all debt basis adjustments from previously designed fair value hedges prior to 2018 so there is no scheduled amortization for previously terminated fair value hedges that will impact the Bank’s financial statements for the foreseeable future. Cash Flow Hedges – During the first quarter of 2019 , the Bank had two receive-fixed interest rate swaps that were designated as cash flow hedges mature. The Bank layered on an additional seven swaps in its cash flow hedge portfolio as part of its efforts to reduce asset-sensitivity and exposure to potential net interest income and margin compression in a down interest rate environment scenario. The seven additional swaps designated as cash flow hedges ranged from three to five years in tenor and increased the Bank’s overall swap notional designation in qualifying cash flow hedges of commercial loans from approximately $700 million as of December 31, 2018 , to approximately $1.3 billion as of March 31, 2019 . The Bank’s overall cash flow hedge swap portfolio as of the balance sheet date has a weighted-average maturity date of 2.7 years and a weighted average received-fixed strike rate of 2.08% , with a total of 22 active swaps and an additional five swaps maturing during 2019 with an aggregate notional of $150 million . Additionally, during the first quarter of 2019 , the Bank expanded its existing cash flow hedging program by introducing purchased floors as hedging instruments of its commercial loan portfolio. In total the Bank purchased $3 billion of floors with strike rates at 1.5% on one-month Intercontinental Exchange LIBOR. The $3 billion floors are composed of six individual purchased floors, all with a notional of $500 million and a tenor of approximately three years. Floors purchased were spread across the entire first quarter of 2019 and had an aggregate purchase premium of $7 million , and by March 31, 2019 , the floor had increased in value to approximately $9 million dollars. The premium is amortized on a straight-line basis over the life of the derivative with changes in fair value deferred in other comprehensive income (“OCI”) as long as the hedging relationship remains highly effective and qualifies for hedge accounting. Amounts deferred in OCI are reclassified into earning in the periods in which the hedged forecasted transactions effect earnings. Collateral and Credit Risk Exposure to credit risk arises from the possibility of nonperformance by counterparties. No significant losses on derivative instruments have occurred as a result of counterparty nonperformance. For a more detailed discussion of collateral and credit risk related to our derivative contracts, see Note 7 of our 2018 Annual Report on Form 10-K. Our derivative contracts require us to pledge collateral for derivatives that are in a net liability position at a given balance sheet date. Certain of these derivative contracts contain credit-risk-related contingent features that include the requirement to maintain a minimum debt credit rating. We may be required to pledge additional collateral if a credit-risk-related feature were triggered, such as a downgrade of our credit rating. However, in past situations, not all counterparties have demanded that additional collateral be pledged when provided for by the contractual terms. At March 31, 2019 , the fair value of our derivative liabilities was $25 million , for which we were required to pledge cash collateral of approximately $50 million in the normal course of business. If our credit rating were downgraded one notch by either Standard & Poor’s (“S&P”) or Moody’s at March 31, 2019 , there would likely be $1 million additional collateral required to be pledged. As a result of the Dodd-Frank Wall Street Reform and Consumer Protection Act (“Dodd-Frank Act”), all newly eligible derivatives entered into are cleared through a central clearinghouse. Derivatives that are centrally cleared do not have credit-risk-related features that require additional collateral if our credit rating were downgraded. Derivative Amounts Selected information with respect to notional amounts and recorded gross fair values at March 31, 2019 and December 31, 2018 , and the related gain (loss) of derivative instruments for the three months ended March 31, 2019 and 2018 is summarized as follows: March 31, 2019 December 31, 2018 Notional amount Fair value Notional amount Fair value (In millions) Other assets Other liabilities Other assets Other liabilities Derivatives designated as hedging instruments: Cash flow hedges: Purchased interest rate floors $ 3,000 $ 9 $ — $ — $ — $ — Received-fixed interest rate swaps 1,338 — — 687 — — Fair value hedges: Received-fixed interest rate swaps 1,000 — — 500 — — Total derivatives designated as hedging instruments 5,338 9 — 1,187 — — Derivatives not designated as hedging instruments: Customer-facing interest rate derivatives 3,035 69 22 2,826 40 36 Offsetting interest rate derivatives 3,035 — — 2,826 — — Other interest rate derivatives 449 1 1 253 1 1 Foreign exchange derivatives 367 3 2 389 4 2 Total derivatives not designated as hedging instruments 6,886 73 25 6,294 45 39 Total derivatives $ 12,224 $ 82 $ 25 $ 7,481 $ 45 $ 39 Amount of derivative gain (loss) recognized/reclassified Three Months Ended March 31, 2019 Three Months Ended March 31, 2018 (In millions) OCI Reclassified from AOCI to interest income Noninterest income (expense) Offset to interest expense OCI Reclassified from AOCI to interest income Noninterest Offset to Derivatives designated as hedging instruments: Cash flow hedges of floating-rate assets 1 : Purchased interest rate floors $ 3 $ — $ (5 ) $ — Interest rate swaps 8 2 Fair value hedges of fixed-rate debt: Receive-fixed interest rate swaps $ — $ — Total derivatives designated as hedging instruments 11 2 — (5 ) — — Derivatives not designated as hedging instruments: Customer-facing interest rate derivatives $ (41 ) $ 45 Offsetting interest rate derivatives 44 (38 ) Other interest rate derivatives — (2 ) Foreign exchange derivatives 5 5 Total derivatives not designated as hedging instruments 8 10 Total derivatives $ 11 $ 2 $ 8 $ — $ (5 ) $ — $ 10 $ — Note: These schedules are not intended to present at any given time the Bank’s long/short position with respect to its derivative contracts. 1 Amounts recognized in OCI and reclassified from AOCI represent the effective portion of the derivative gain (loss). For the 12 months following March 31, 2019 , we estimate that $(7) million will be reclassified from AOCI into interest income The following schedule presents derivatives used in fair value hedge accounting relationships, as well as pre-tax gains/(losses) recorded on such derivatives and the related hedged items for the periods presented. Gain/(loss) recorded in income Three Months Ended March 31, 2019 Three Months Ended March 31, 2018 (In millions) Derivatives 2 Hedged items Total income statement impact Derivatives 2 Hedged items Total income statement impact Interest rate swaps 1 $ 6 $ (6 ) $ — $ — $ — $ — 1 Consists of hedges of benchmark interest rate risk of fixed-rate long-term debt. Gains and losses were recorded in net interest income. 2 The income for the derivative does not reflect interest income/expense to be consistent with the presentation of the gains/ (losses) on the hedged items. The following schedule provides selected information regarding the long-term debt in the statement of financial position in which the hedged item is included. Carrying amount of the hedged assets/(liabilities) Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged assets/(liabilities) (In millions) March 31, 2019 December 31, 2018 March 31, 2019 December 31, 2018 Long-term debt $ (1,010 ) $ (505 ) $ (10 ) $ (5 ) The fair value of derivative assets was reduced by a net credit valuation adjustment of $6 million and $1 million at March 31 , 2019 and 2018 , respectively. The adjustment for derivative liabilities was a decrease of less than $1 million at March 31 , 2019 and $1 million at March 31 , 2018 . These adjustments are required to reflect both our own nonperformance risk and the respective counterparty’s nonperformance risk.

Leases Leases

Leases Leases	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Lessee, Operating Leases [Text Block]	LEASES Leases In February 2016, the FASB issued ASU 2016-02, Leases (“Topic 842”), to increase transparency and comparability among organizations by requiring the recognition of right-of-use assets and lease liabilities on the balance sheet. Most prominent among the changes in the standard is the recognition of right-of-use (“ROU”) assets and lease liabilities by lessees for those leases classified as operating leases. Under the standard, disclosures are required to meet the objective of enabling users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. Upon adoption the Bank has elected to use the following optional exemptions that are permitted under Topic 842, which have been applied consistently: • the Bank elected the optional transition method and recorded an immaterial cumulative-effect adjustment to retained earnings to recognize the appropriate amount of lease assets and liabilities on the balance sheet as of the adoption date of the standard. Prior period financial statements were not restated. • the Bank elected the expedient package to not reassess (1) whether any existing or expired contracts are or contain leases, (2) lease classification for any existing or expired leases, and (3) initial direct costs for any existing leases. • the Bank elected to not separate lease components from non-lease components for all classes of underlying assets for lessee or lessor transactions. We determine if a contract is a lease or contains a lease at inception. The right to use leased assets for the lease term are considered ROU assets. Operating lease assets are included in “Other assets” while finance lease assets are included in “Premises, equipment and software, net.” Lease liabilities for operating leases are included in “Other liabilities” while finance leases are included in “Long-term debt” on our consolidated balance sheet. Lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. Because most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of future payments. The lease ROU asset also incorporates any amortization incurred, including initial direct costs, and excludes lease incentives received. Our lease terms may include options to extend or terminate the lease, and the lease term incorporates these when it is reasonably certain that we will exercise these options. The Bank enters into certain lease agreements with both lease and non-lease components, which are not separated out for lessees and lessors on a relative standalone basis. We have operating and finance leases for branches, corporate offices, and data centers. Our equipment leases are not material. At March 31, 2019 , we had 433 branches, of which 276 are owned and 157 are leased. We lease our headquarters in Salt Lake City, Utah, and other office or data centers are either owned or leased. The Bank may enter into certain lease arrangements with a term of 12 months or less, and it has elected to exclude these from capitalization. The length of our commitments for leases ranges from 2019 to 2062 , some of which include options to extend or terminate the leases. As of March 31, 2019 , assets recorded under operating leases were $244 million , while assets recorded under finance leases were less than $1 million . We utilized a secured incremental borrowing rate based on the remaining term of the lease as of the effective date for the discount rate to determine our lease ROU assets and liabilities. The following schedule presents lease-related assets, their weighted average remaining life, and the weighted average discount rate. (Dollar amounts in millions) March 31, Operating Operating right-of-use assets $ 244 Operating lease liabilities 252 Weighted average remaining lease term (years) Operating leases 9.4 Finance leases 1.1 Weighted average discount rate Operating leases 3.2 % Finance leases 13.1 % The components of lease expense are as follows: (In millions) Three Months Ended March 31, 2019 Operating lease costs $ 12 Variable lease costs 13 Total lease cost $ 25 Supplemental cash flow information related to leases is as follows: (In millions) Three Months Ended March 31, 2019 Cash paid for amounts in the measurement of lease liabilities: Operating cash disbursements from operating leases $ 10 Maturities analysis for lease liabilities as of March 31, 2019 is as follows (undiscounted lease payments): (In millions) 2019 1 $ 41 2020 45 2021 39 2022 35 2023 31 Thereafter 114 Total $ 305 1 Contractual maturities for the nine months remaining in 2019. The Bank enters into certain lease agreements where it is the lessor of real estate. Real estate leases are made from bank-owned and subleased property to generate cash flow from the property, including from leasing vacant suites in which the Bank occupies portions of the building. Operating lease income was $2 million and $3 million for the first three months of 2019 and 2018 , respectively. Maturities analysis of operating lease payments to be received as of March 31, 2019 is as follows: (In millions) 2019 1 $ 6 2020 8 2021 8 2022 7 2023 7 Thereafter 25 Total $ 61 1 Contractual maturities for the nine months remaining in 2019. The Bank also has a lending division that makes equipment leases, considered to be sales-type leases or direct financing leases, totaling $312 million and $371 million as of March 31, 2019 and 2018 , respectively. The Bank uses leasing of equipment as a venue for customers to access equipment without purchasing upfront. For the first quarters of 2019 and 2018 , the Bank recorded income of $4 million and $3 million on these leases.
Lessor, Operating Lease, Payments to be Received, Maturity [Table Text Block]	(In millions) 2019 1 $ 6 2020 8 2021 8 2022 7 2023 7 Thereafter 25 Total $ 61 1 Contractual maturities for the nine months remaining in 2019.
Lessee, Operating Lease, Assumptions and Judgments, Discount Rate, Description	(Dollar amounts in millions) March 31, Operating Operating right-of-use assets $ 244 Operating lease liabilities 252 Weighted average remaining lease term (years) Operating leases 9.4 Finance leases 1.1 Weighted average discount rate Operating leases 3.2 % Finance leases 13.1 %

Debt And Shareholders' Equity

Debt And Shareholders' Equity	3 Months Ended
	Mar. 31, 2019
Capitalization, Long-term Debt and Equity [Abstract]
Debt And Shareholders' Equity	LONG-TERM DEBT AND SHAREHOLDERS’ EQUITY Long-Term Debt Long-term debt is summarized as follows: (In millions) March 31, December 31, 2018 Subordinated notes $ 87 $ 87 Senior notes 1,141 637 Total $ 1,228 $ 724 The preceding carrying values represent the par value of the debt adjusted for any unamortized premium or discount or unamortized debt issuance costs as well as valuation adjustments for fair value swaps. During the first quarter of 2019, the Bank issued a $500 million senior note with an interest rate of 3.35% and a maturity date of March 4, 2022. Common Stock and Common Stock Warrants The Bank’s common stock is traded on the National Association of Securities Dealers Automated Quotations (“NASDAQ”) Global Select Market. As of March 31, 2019, there were 182.5 million shares of 0.001 par value common stock outstanding. As of March 31, 2019, 29.3 million common stock warrants (NASDAQ: ZIONW), with an exercise price of $34.61 , were outstanding, and each common stock warrant was convertible into 1.06 shares. These warrants expire on May 22, 2020. Repurchases of Bank Common Stock During the first quarter of 2019 , we continued our common stock buyback program and repurchased 5.5 million shares of common stock outstanding with a fair value of $275 million at an average price of $50.03 per share. During the first quarter of 2018 , we repurchased 2.2 million shares of common stock outstanding with a fair value of $115 million , at an average price of $53.46 per share. In April 2019, the Bank announced that the Board approved a plan to repurchase $275 million of common stock during the second quarter of 2019. Accumulated Other Comprehensive Income Accumulated other comprehensive income (loss) was $(122) million at March 31, 2019 compared with $(250) million at December 31, 2018 . Changes in AOCI by component are as follows: (In millions) Net unrealized gains (losses) on investment securities Net unrealized gains (losses) on derivatives and other Pension and post-retirement Total Three Months Ended March 31, 2019 Balance at December 31, 2018 $ (228 ) $ (1 ) $ (21 ) $ (250 ) OCI before reclassifications, net of tax 122 5 — 127 Amounts reclassified from AOCI, net of tax — 1 — 1 OCI 122 6 — 128 Balance at March 31, 2019 $ (106 ) $ 5 $ (21 ) $ (122 ) Income tax expense included in OCI $ 40 $ 2 $ — $ 42 Three Months Ended March 31, 2018 Balance at December 31, 2017 $ (114 ) $ (2 ) $ (23 ) $ (139 ) OCI (loss) before reclassifications, net of tax (126 ) (2 ) — (128 ) Amounts reclassified from AOCI, net of tax — — — — OCI (loss) (126 ) (2 ) — (128 ) Balance at March 31, 2018 $ (240 ) $ (4 ) $ (23 ) $ (267 ) Income tax benefit included in OCI $ (41 ) $ (1 ) $ — $ (42 ) Amounts reclassified from AOCI 1 Statement of income (SI) Balance sheet (BS) (In millions) Three Months Ended Details about AOCI components 2019 2018 Affected line item Net unrealized losses on derivative instruments $ (1 ) $ — SI Interest and fees on loans Income tax benefit — — Amounts Reclassified from AOCI $ (1 ) $ — 1 Negative reclassification amounts indicate decreases to earnings in the statement of income and increases to balance sheet assets.

Commitments, Guarantees, And Co

Commitments, Guarantees, And Contingent Liabilities	3 Months Ended
	Mar. 31, 2019
Guarantees, Commitments And Contingencies [Abstract]
Guarantees, Commitments And Contingencies	COMMITMENTS, GUARANTEES AND CONTINGENT LIABILITIES Commitments and Guarantees Contractual amounts of off-balance sheet financial instruments used to meet the financing needs of our customers are as follows: (In millions) March 31, December 31, Net unfunded commitments to extend credit 1 $ 21,632 $ 21,454 Standby letters of credit: Financial 544 655 Performance 196 199 Commercial letters of credit 27 18 Total unfunded lending commitments $ 22,399 $ 22,326 1 Net of participations The Bank’s 2018 Annual Report on Form 10-K contains further information about these commitments and guarantees including their terms and collateral requirements. At March 31, 2019 , the Bank had recorded approximately $4 million as a liability for the guarantees associated with the standby letters of credit, which consisted of $1 million attributable to the RULC and $3 million of deferred commitment fees. Legal Matters We are subject to litigation in court and arbitral proceedings, as well as proceedings, investigations, examinations and other actions brought or considered by governmental and self-regulatory agencies. Litigation may relate to lending, deposit and other customer relationships, vendor and contractual issues, employee matters, intellectual property matters, personal injuries and torts, regulatory and legal compliance, and other matters. While most matters relate to individual claims, we are also subject to putative class action claims and similar broader claims. Proceedings, investigations, examinations and other actions brought or considered by governmental and self-regulatory agencies may relate to our banking, investment advisory, trust, securities, and other products and services; our customers’ involvement in money laundering, fraud, securities violations and other illicit activities or our policies and practices relating to such customer activities; and our compliance with the broad range of banking, securities and other laws and regulations applicable to us. At any given time, we may be in the process of responding to subpoenas, requests for documents, data and testimony relating to such matters and engaging in discussions to resolve the matters. As of March 31, 2019 , we were subject to the following material litigation or governmental inquiries: • a civil suit, Shou-En Wang v. CB&T, brought against us in the Superior Court for Los Angeles County, Central District in April 2016. The case relates to our depositor relationships with customers who were promoters of an investment program that allegedly misappropriated investors’ funds. Initial motion practice and discovery have been completed. Additional motion practice and expert witness phases are underway. • a civil suit, McFarland as Trustee for International Manufacturing Group v. CB&T, et. al. , brought against us in the United States Bankruptcy Court for the Eastern District of California in May 2016. The Trustee seeks to recover loan payments previously repaid to us by our customer, International Manufacturing Group (“IMG”), alleging that IMG, along with its principal, obtained loans and made loan repayments in furtherance of an alleged Ponzi scheme. Initial motion practice has been completed and discovery is underway. • a civil suit, JTS Communities, Inc. et. al v. CB&T, Jun Enkoji and Dawn Satow , brought against us in the Superior Court for Sacramento County, California in June 2017. In this case four investors in IMG seek to hold us liable for losses arising from their investments in that company, alleging that we conspired with and knowingly assisted IMG and its principal in furtherance of an alleged Ponzi scheme. This case is in an early phase with initial motion practice having been completed and discovery is underway. • a civil class action lawsuit, Evans v. CB&T , brought against us in the United States District Court for the Eastern District of California in May 2017. This case was filed on behalf of a class of up to 50 investors in IMG and seeks to hold us liable for losses of class members arising from their investments in IMG, alleging that we conspired with and knowingly assisted IMG and its principal in furtherance of an alleged Ponzi scheme. In December 2017, the District Court dismissed all claims against the Bank. In January 2018, the plaintiff filed an appeal with the Court of Appeals for the Ninth Circuit. The appeal was heard in early April 2019 and a ruling is anticipated in mid or late 2019. • a Private Attorney General Act (“PAGA”) claim under California law, Lawson v. CB&T , brought against us in the Superior Court for the County of San Diego, California, in February 2016. In this case, the plaintiff alleges, on behalf of herself and other current or former employees of the Bank who worked in California on a non-exempt basis, violations by the Bank of California wage and hour laws. The case remains in the early stages of motion practice, to date mainly involving questions of venue and scope of employees covered by the PAGA claims. In March 2018, the Supreme Court of California granted review of an appeal from the intermediate appellate court decision requiring all aspects of the case to be heard in state court, rather than in arbitration. The appellate briefing process has been completed with a ruling anticipated in 2019. • two civil cases, Lifescan Inc. and Johnson & Johnson Health Care Services v. Jeffrey Smith, et. al. , brought against us in the United States District Court for the District of New Jersey in December 2017 and Roche Diagnostics and Roche Diabetes Care Inc. v. Jeffrey C. Smith, et. al. , brought against us in the United States District Court for the District of New Jersey in March 2019. In these cases, certain manufacturers and distributors of medical products seek to hold us liable for allegedly fraudulent practices of a borrower of the Bank which filed for bankruptcy protection in 2017. The cases are in early phases, with initial motion practice and discovery underway in the Lifescan case. • two civil class action lawsuits: Gregory, et. al. v. Zions Bancorporation and Springer, et. al. v. Zions Bancorporation , were brought against us in the United States District Court in Utah in January 2019 which have been consolidated into one case; and a separate civil action brought by a group of investors North Valley Partners, et. al. v. Zions Bancorporation , brought against us in the Third Judicial District Court for Salt Lake County, in March 2019. These cases were filed on behalf of investors in Rust Rare Coin, Inc. alleging that we aided and abetted a Ponzi scheme fraud perpetrated by Rust Rare Coin, a Zions Bank customer. The cases follow civil actions and the establishment of a receivership for Rust Rare Coin by The Commodities Futures Trading Commission and the Utah Division of Securities in November 2018, as well as a separate suit brought by the Securities and Exchange Commission against Rust Rare Coin and its principal, Gaylen Rust. At least quarterly, we review outstanding and new legal matters, utilizing then available information. In accordance with applicable accounting guidance, if we determine that a loss from a matter is probable and the amount of the loss can be reasonably estimated, we establish an accrual for the loss. In the absence of such a determination, no accrual is made. Once established, accruals are adjusted to reflect developments relating to the matters. In our review, we also assess whether we can determine the range of reasonably possible losses for significant matters in which we are unable to determine that the likelihood of a loss is remote. Because of the difficulty of predicting the outcome of legal matters, discussed subsequently, we are able to meaningfully estimate such a range only for a limited number of matters. Based on information available as of March 31, 2019 , we estimated that the aggregate range of reasonably possible losses for those matters to be from $0 million to roughly $50 million in excess of amounts accrued. The matters underlying the estimated range will change from time to time, and actual results may vary significantly from this estimate. Those matters for which a meaningful estimate is not possible are not included within this estimated range and, therefore, this estimated range does not represent our maximum loss exposure. Based on our current knowledge, we believe that our current estimated liability for litigation and other legal actions and claims, reflected in our accruals and determined in accordance with applicable accounting guidance, is adequate and that liabilities in excess of the amounts currently accrued, if any, arising from litigation and other legal actions and claims for which an estimate as previously described is possible, will not have a material impact on our financial condition, results of operations, or cash flows. However, in light of the significant uncertainties involved in these matters, and the very large or indeterminate damages sought in some of these matters, an adverse outcome in one or more of these matters could be material to our financial condition, results of operations, or cash flows for any given reporting period. Any estimate or determination relating to the future resolution of litigation, arbitration, governmental or self-regulatory examinations, investigations or actions or similar matters is inherently uncertain and involves significant judgment. This is particularly true in the early stages of a legal matter, when legal issues and facts have not been well articulated, reviewed, analyzed, and vetted through discovery, preparation for trial or hearings, substantive and productive mediation or settlement discussions, or other actions. It is also particularly true with respect to class action and similar claims involving multiple defendants, matters with complex procedural requirements or substantive issues or novel legal theories, and examinations, investigations and other actions conducted or brought by governmental and self-regulatory agencies, in which the normal adjudicative process is not applicable. Accordingly, we usually are unable to determine whether a favorable or unfavorable outcome is remote, reasonably likely, or probable, or to estimate the amount or range of a probable or reasonably likely loss, until relatively late in the course of a legal matter, sometimes not until a number of years have elapsed. Accordingly, our judgments and estimates relating to claims will change from time to time in light of developments and actual outcomes will differ from our estimates. These differences may be material.

Revenue Recognition Revenue Rec

Revenue Recognition Revenue Recognition (Notes)	3 Months Ended
	Mar. 31, 2019
Revenue Recognition and Deferred Revenue [Abstract]
Deferred Revenue, by Arrangement, Disclosure [Table Text Block]	REVENUE RECOGNITION We derive our revenue primarily from interest income on loans and securities, which was more than three-quarters of our revenue in the first quarter of 2019 . Only noninterest income is considered to be revenue from contracts with customers in scope of ASC 606. For a discussion of the Bank’s revenue recognition from contracts, and the implementation of ASC 606, see Note 16 of our 2018 Annual Report on Form 10-K. The following schedule provides the major income categories within “Other service charges, commissions and fees” that are in scope of ASC 606 for the three months ended March 31, 2019 : Three Months Ended (In millions) 2019 2018 Card fee income $ 34 $ 33 ATM fees 2 2 Other service charges 3 4 Other commissions and fees 4 5 Total $ 43 $ 44 Disaggregation of Revenue We provide services across different geographical areas, primarily in 11 Western U.S. States, under banking operations that have their own individual brand names, including Zions Bank, Amegy Bank, California Bank & Trust, National Bank of Arizona, Nevada State Bank, Vectra Bank Colorado, and The Commerce Bank of Washington. The operating segment listed as “Other” includes Zions Management Services Company, certain nonbank financial services subsidiaries, centralized back-office functions, and eliminations of transactions between the segments. Certain prior period amounts have been reclassified to conform with the current period presentation. These reclassifications did not affect net income or shareholders’ equity. The following schedule sets forth the noninterest income and net revenue by operating segments for the three months ended March 31, 2019 and 2018 : Zions Bank Amegy CB&T (In millions) 2019 2018 2019 2018 2019 2018 Service charges and fees on deposit accounts $ 13 $ 15 $ 11 $ 10 $ 7 $ 7 Other service charges, commissions, and fees 17 16 9 8 7 5 Wealth management and trust income 4 4 3 2 1 1 Capital markets and foreign exchange 1 1 (1 ) (2 ) 1 1 Total noninterest income from contracts with customers (ASC 606) 35 36 22 18 16 14 Other noninterest income (Non-ASC 606 customer related) (3 ) (2 ) 13 12 4 4 Total customer-related fees 32 34 35 30 20 18 Other noninterest income (non-customer related) 1 1 (1 ) 2 (1 ) 3 Total noninterest income 33 35 34 32 19 21 Other real estate owned gain from sale 1 1 — — — — Net interest income 180 167 131 127 138 131 Total income less interest expense $ 214 $ 203 $ 165 $ 159 $ 157 $ 152 NBAZ NSB Vectra (In millions) 2019 2018 2019 2018 2019 2018 Service charges and fees on deposit accounts $ 3 $ 3 $ 4 $ 4 $ 2 $ 2 Other service charges, commissions, and fees 3 2 3 3 2 3 Wealth management and trust income — 1 1 1 — — Capital markets and foreign exchange — — — — — — Total noninterest income from contracts with customers (ASC 606) 6 6 8 8 4 5 Other noninterest income (Non-ASC 606 customer related) 3 2 2 2 1 1 Total customer-related fees 9 8 10 10 5 6 Other noninterest income (non-customer related) 1 1 — — 1 — Total noninterest income 10 9 10 10 6 6 Other real estate owned gain from sale — — — — — — Net interest income 60 53 40 35 36 32 Total income less interest expense $ 70 $ 62 $ 50 $ 45 $ 42 $ 38 TCBW Other Consolidated Bank (In millions) 2019 2018 2019 2018 2019 2018 Service charges and fees on deposit accounts $ — $ — $ — $ 1 $ 40 $ 42 Other service charges, commissions, and fees 1 1 1 6 43 44 Wealth management and trust income — — 4 3 13 12 Capital markets and foreign exchange — — 2 3 3 3 Total noninterest income from contracts with customers (ASC 606) 1 1 7 13 99 101 Other noninterest income (Non-ASC 606 customer related) — — 1 3 21 22 Total customer-related fees 1 1 8 16 120 123 Other noninterest income (non-customer related) — — 11 8 12 15 Total noninterest income 1 1 19 24 132 138 Other real estate owned gain from sale — — — — 1 1 Net interest income 14 11 (23 ) (14 ) 576 542 Total income less interest expense $ 15 $ 12 $ (4 ) $ 10 $ 709 $ 681 Revenue from contracts with customers did not generate significant contract assets and liabilities. Contract receivables are included in Other Assets. Payment terms vary by services offered, and the timing between completion of performance obligations and payment is typically not significant.

Retirement Plans

Retirement Plans	3 Months Ended
	Mar. 31, 2019
Defined Benefit Plan [Abstract]
Retirement Plans	RETIREMENT PLANS The following discloses the net periodic benefit cost (credit) and its components for the Bank’s pension and other retirement plans: (In millions) Three Months Ended March 31, 2019 2018 Interest cost $ 1 $ 1 Expected return on plan assets (2 ) (3 ) Partial settlement loss — 1 Amortization of net actuarial loss 1 — Net periodic benefit cost (benefit) $ — $ (1 ) As disclosed in our 2018 Annual Report on Form 10-K, the Bank has frozen its participation and benefit accruals for the pension plan and its contributions for individual benefit payments in the postretirement benefit plan. In October 2018, the Bank has decided to terminate its pension plan subject to obtaining necessary regulatory approval. Completion of this termination is expected in early 2020. Plan participant benefits will not be disadvantaged because of this decision.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The effective income tax rate of 22.3% for the first quarter of 2019 was slightly lower than the 2018 first quarter rate of 22.7% . The income tax rates for 2019 and 2018 were reduced by nontaxable municipal interest income and nontaxable income from certain bank-owned life insurance, and were increased by the non-deductibility of Federal Deposit Insurance Corporation (“FDIC”) premiums, certain executive compensation and other fringe benefits. We had a net deferred tax asset (“DTA”) balance of $73 million at March 31, 2019 , compared with $130 million at December 31, 2018 . The decrease in the net DTA resulted primarily from the decrease of accrued compensation and unrealized losses in OCI related to securities. A reduction of net deferred tax liabilities related to leasing operations, including deferred items associated with the adoption of ASC 842, offset some of the overall decrease in DTA.

Net Earnings per Common Share (

Net Earnings per Common Share (Notes)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share [Text Block]	NET EARNINGS PER COMMON SHARE Basic and diluted net earnings per common share based on the weighted average outstanding shares are summarized as follows: Three Months Ended (In millions, except shares and per share amounts) 2019 2018 Basic: Net income $ 213 $ 238 Less common and preferred dividends 64 47 Undistributed earnings 149 191 Less undistributed earnings applicable to nonvested shares 1 1 Undistributed earnings applicable to common shares 148 190 Distributed earnings applicable to common shares 56 39 Total earnings applicable to common shares $ 204 $ 229 Weighted average common shares outstanding (in thousands) 184,767 196,722 Net earnings per common share $ 1.10 $ 1.16 Diluted: Total earnings applicable to common shares $ 204 $ 229 Weighted average common shares outstanding (in thousands) 184,767 196,722 Dilutive effect of common stock warrants (in thousands) 9,739 12,382 Dilutive effect of stock options (in thousands) 735 1,139 Weighted average diluted common shares outstanding (in thousands) 195,241 210,243 Net earnings per common share $ 1.04 $ 1.09 The following schedule presents the weighted average shares of stock awards that were anti-dilutive and not included in the calculation of diluted earnings per share. Three Months Ended (In thousands) 2019 2018 Restricted stock and restricted stock units 1,423 1,757

Operating Segment Information

Operating Segment Information	3 Months Ended
	Mar. 31, 2019
Operating Segment Information [Abstract]
Operating Segment Information	OPERATING SEGMENT INFORMATION We manage our operations and prepare management reports and other information with a primary focus on geographical area. Our banking operations are managed under their own individual brand names, including Zions Bank, Amegy Bank, California Bank & Trust, National Bank of Arizona, Nevada State Bank, Vectra Bank Colorado, and The Commerce Bank of Washington. Performance assessment and resource allocation are based upon this geographical structure. We use an internal funds transfer pricing (“FTP”) allocation system to report results of operations for business segments. This process is continually refined. Total average loans and deposits presented for the banking segments include insignificant intercompany amounts between banking segments and may also include deposits with the Other segment. As of March 31, 2019 , our banking business is conducted through 7 locally managed and branded segments in distinct geographical areas. Zions Bank operates 98 branches in Utah, 23 branches in Idaho, and one branch in Wyoming. Amegy operates 74 branches in Texas. CB&T operates 90 branches in California. NBAZ operates 58 branches in Arizona. NSB operates 50 branches in Nevada. Vectra operates 36 branches in Colorado and one branch in New Mexico. TCBW operates one branch in Washington and one branch in Oregon. The operating segment identified as “Other” includes certain nonbank financial service subsidiaries, centralized back-office functions, and eliminations of transactions between segments. The major components of net interest income at the Bank’s back-office include the revenue associated with the investments securities portfolio and the offset of the FTP costs and benefits provided to the business segments. The following schedule does not present total assets or income tax expense for each operating segment, but instead presents average loans, average deposits and income before income taxes because these are the metrics that management uses when evaluating performance and making decisions pertaining to the operating segments. The Bank’s net interest income includes interest expense on borrowed funds. The condensed statement of income identifies the components of income and expense which affect the operating amounts presented in the Other segment. The accounting policies of the individual operating segments are the same as those of the Bank. Transactions between operating segments are primarily conducted at fair value, resulting in profits that are eliminated for reporting consolidated results of operations. The following schedule presents selected operating segment information for the three months ended March 31, 2019 and 2018 : (In millions) Zions Bank Amegy CB&T 2019 2018 2019 2018 2019 2018 SELECTED INCOME STATEMENT DATA Net interest income $ 180 $ 167 $ 131 $ 127 $ 138 $ 131 Provision for credit losses 11 (2 ) (15 ) (53 ) 3 2 Net interest income after provision for loan losses 169 169 146 180 135 129 Noninterest income 33 35 34 32 19 21 Noninterest expense 118 113 88 87 82 77 Income (loss) before income taxes $ 84 $ 91 $ 92 $ 125 $ 72 $ 73 SELECTED AVERAGE BALANCE SHEET DATA Total average loans $ 12,939 $ 12,453 $ 11,861 $ 11,370 $ 10,574 $ 9,929 Total average deposits 15,524 15,712 11,441 10,816 11,243 11,119 (In millions) NBAZ NSB Vectra 2019 2018 2019 2018 2019 2018 SELECTED INCOME STATEMENT DATA Net interest income $ 60 $ 53 $ 40 $ 35 $ 36 $ 32 Provision for credit losses 3 2 (1 ) — 4 3 Net interest income after provision for loan losses 57 51 41 35 32 29 Noninterest income 10 9 10 10 6 6 Noninterest expense 39 38 36 36 28 27 Income (loss) before income taxes $ 28 $ 22 $ 15 $ 9 $ 10 $ 8 SELECTED AVERAGE BALANCE SHEET DATA Total average loans $ 4,749 $ 4,543 $ 2,500 $ 2,348 $ 3,055 $ 2,794 Total average deposits 4,894 4,783 4,329 4,223 2,821 2,711 (In millions) TCBW Other Consolidated Bank 2019 2018 2019 2018 2019 2018 SELECTED INCOME STATEMENT DATA Net interest income $ 14 $ 11 $ (23 ) $ (14 ) $ 576 $ 542 Provision for credit losses — 1 (1 ) — 4 (47 ) Net interest income after provision for loan losses 14 10 (22 ) (14 ) 572 589 Noninterest income 1 1 19 24 132 138 Noninterest expense 6 6 33 35 430 419 Income (loss) before income taxes $ 9 $ 5 $ (36 ) $ (25 ) $ 274 $ 308 SELECTED AVERAGE BALANCE SHEET DATA Total average loans $ 1,110 $ 1,084 $ 383 $ 343 $ 47,171 $ 44,864 Total average deposits 1,075 1,073 2,589 1,557 53,916 51,994

Basis of Presentaion Organizati

Basis of Presentaion Organization and Presentation (Policies)	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	BASIS OF PRESENTATION The accompanying unaudited consolidated financial statements of Zions Bancorporation, National Association and its majority-owned subsidiaries (collectively “Zions Bancorporation, N.A.,” “the Bank,” “we,” “our,” “us”) have been prepared in accordance with United States (“U.S.”) generally accepted accounting principles (“GAAP”) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. References to GAAP, including standards promulgated by the Financial Accounting Standards Board (“FASB”), are made according to sections of the Accounting Standards Codification (“ASC”). Changes to the ASC are made with Accounting Standards Updates (“ASU”) that include consensus issues of the Emerging Issues Task Force. Operating results for the three months ended March 31, 2019 and 2018 are not necessarily indicative of the results that may be expected in future periods. In preparing the consolidated financial statements, we are required to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. The consolidated balance sheet at December 31, 2018 is from the audited financial statements at that date, but does not include all of the information and footnotes required by GAAP for complete financial statements. For further information, refer to the consolidated financial statements and footnotes thereto included in the Bank’s 2018 Annual Report on Form 10-K. Certain prior period amounts have been reclassified to conform with the current period presentation. These reclassifications did not affect net income or shareholders’ equity. Zions Bancorporation, N.A. is a commercial bank headquartered in Salt Lake City, Utah. The Bank provides a full range of banking and related services in 11 Western and Southwestern states through 7 separately managed and branded units as follows: Zions Bank, in Utah, Idaho and Wyoming; Amegy Bank (“Amegy”), in Texas; California Bank & Trust (“CB&T”); National Bank of Arizona (“NBAZ”); Nevada State Bank (“NSB”); Vectra Bank Colorado (“Vectra”), in Colorado and New Mexico; and The Commerce Bank of Washington (“TCBW”) which operates under that name in Washington and under the name The Commerce Bank of Oregon in Oregon.

Fair Value (Tables)

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Schedule Of Assets And Liabilities Measured At Fair Value By Class On A Recurring Basis	(In millions) March 31, 2019 Level 1 Level 2 Level 3 Total ASSETS Investment securities: Available-for-sale: 1 U.S. Treasury, agencies and corporations $ 40 $ 13,559 $ — $ 13,599 Municipal securities 1,283 1,283 Other debt securities 22 22 Total Available-for-sale 40 14,864 — 14,904 Trading account 161 155 316 Other noninterest-bearing investments: Bank-owned life insurance 518 518 Private equity investments 107 107 Other assets: Agriculture loan servicing and interest-only strips 17 17 Deferred compensation plan assets 107 107 Derivatives: Derivatives designated as hedges 9 9 Derivatives not designated as hedges: Customer-facing interest rate 69 69 Other interest rate 1 1 Foreign exchange 3 3 Total Assets $ 311 $ 15,616 $ 124 $ 16,051 LIABILITIES Securities sold, not yet purchased $ 52 $ — $ — $ 52 Other liabilities: Deferred compensation plan obligations 107 107 Derivatives: Derivatives not designated as hedges: Customer-facing interest rate 22 22 Other interest rate 1 1 Foreign exchange 2 2 Total Liabilities $ 161 $ 23 $ — $ 184 1 We used a third-party pricing service to measure fair value for approximately 94% of our AFS Level 2 securities. (In millions) December 31, 2018 Level 1 Level 2 Level 3 Total ASSETS Investment securities: Available-for-sale: 1 U.S. Treasury, agencies and corporations $ 40 $ 13,385 $ — $ 13,425 Municipal securities 1,291 1,291 Other debt securities 21 21 Total Available-for-sale 40 14,697 — 14,737 Trading account 14 92 106 Other noninterest-bearing investments: Bank-owned life insurance 516 516 Private equity investments 102 102 Other assets: Agriculture loan servicing and interest-only strips 18 18 Deferred compensation plan assets 95 95 Derivatives: Derivatives not designated as hedges: Customer-facing interest rate 40 40 Other interest rate 1 1 Foreign exchange 4 4 Total Assets $ 153 $ 15,346 $ 120 $ 15,619 LIABILITIES Securities sold, not yet purchased $ 85 $ — $ — $ 85 Other liabilities: Deferred compensation plan obligations 95 95 Derivatives: Derivatives not designated as hedges: Customer-facing interest rate 36 36 Other interest rate 1 1 Foreign exchange 2 2 Total Liabilities $ 182 $ 37 $ — $ 219 1 We used a third-party pricing service to measure fair value for approximately 95% of our AFS Level 2 securities.
Schedule Of Assets And Liabilities Measured At Fair Value By Class On A Recurring Basis Using Level 3 Inputs	Level 3 Instruments Three Months Ended March 31, 2019 March 31, 2018 (In millions) Private Ag loan svcg and int-only strips Private Ag loan svcg and int-only strips Balance at beginning of period $ 102 $ 18 $ 95 $ 18 Securities gains (losses), net 1 — — — Other noninterest income — (1 ) — — Purchases 4 — 5 — Balance at end of period $ 107 $ 17 $ 100 $ 18
Schedule Of Assets With Fair Value Changes On Nonrecurring Basis	(In millions) Fair value at March 31, 2019 Fair value at December 31, 2018 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total ASSETS Private equity investments $ — $ — $ — $ — $ — $ — $ 1 $ 1 Impaired loans — 2 — 2 — 32 — 32 Other real estate owned — 1 — 1 — — — — Total $ — $ 3 $ — $ 3 $ — $ 32 $ 1 $ 33 The previous fair values may not be current as of the dates indicated, but rather as of the date the fair value change occurred, such as a charge for impairment. Accordingly, carrying values may not equal current fair value. Gains (losses) from fair value changes (In millions) Three Months Ended 2019 2018 ASSETS Private equity investments $ — $ — Impaired loans (4 ) (4 ) Other real estate owned — (1 ) Total $ (4 ) $ (5 )
Fair Value, by Balance Sheet Grouping [Table Text Block]	March 31, 2019 December 31, 2018 (In millions) Carrying value Estimated fair value Level Carrying value Estimated fair value Level Financial assets: HTM investment securities $ 764 $ 762 2 $ 774 $ 767 2 Loans and leases (including loans held for sale), net of allowance 47,178 46,197 3 46,312 45,251 3 Financial liabilities: Time deposits 4,928 4,921 2 4,336 4,319 2 Long-term debt 1,228 1,240 2 724 727 2 March 31, 2019 (In millions) Gross amounts not offset in the balance sheet Description Gross amounts recognized Gross amounts offset in the balance sheet Net amounts presented in the balance sheet Financial instruments Cash collateral received/pledged Net amount Assets: Federal funds sold and security resell agreements $ 739 $ (301 ) $ 438 $ — $ — $ 438 Derivatives (included in other assets) 82 — 82 (21 ) (5 ) 56 Total assets $ 821 $ (301 ) $ 520 $ (21 ) $ (5 ) $ 494 Liabilities: Federal funds and other short-term borrowings $ 5,245 $ (301 ) $ 4,944 $ — $ — $ 4,944 Derivatives (included in other liabilities) 25 — 25 (21 ) — 4 Total Liabilities $ 5,270 $ (301 ) $ 4,969 $ (21 ) $ — $ 4,948 December 31, 2018 (In millions) Gross amounts not offset in the balance sheet Description Gross amounts recognized Gross amounts offset in the balance sheet Net amounts presented in the balance sheet Financial instruments Cash collateral received/pledged Net amount Assets: Federal funds sold and security resell agreements $ 1,461 $ — $ 1,461 $ — $ — $ 1,461 Derivatives (included in other assets) 45 — 45 (35 ) (3 ) 7 Total assets $ 1506 $ — $ 1506 $ (35 ) $ (3 ) $ 1468 Liabilities: Federal funds and other short-term borrowings $ 5,653 $ — $ 5,653 $ — $ — $ 5,653 Derivatives (included in other liabilities) 39 — 39 (35 ) (1 ) 3 Total Liabilities $ 5,692 $ — $ 5,692 $ (35 ) $ (1 ) $ 5,656

Offsetting Assets and Liabili_2

Offsetting Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2019
Offsetting Assets and Liabilities [Abstract]
Fair Value, by Balance Sheet Grouping [Table Text Block]	March 31, 2019 December 31, 2018 (In millions) Carrying value Estimated fair value Level Carrying value Estimated fair value Level Financial assets: HTM investment securities $ 764 $ 762 2 $ 774 $ 767 2 Loans and leases (including loans held for sale), net of allowance 47,178 46,197 3 46,312 45,251 3 Financial liabilities: Time deposits 4,928 4,921 2 4,336 4,319 2 Long-term debt 1,228 1,240 2 724 727 2 March 31, 2019 (In millions) Gross amounts not offset in the balance sheet Description Gross amounts recognized Gross amounts offset in the balance sheet Net amounts presented in the balance sheet Financial instruments Cash collateral received/pledged Net amount Assets: Federal funds sold and security resell agreements $ 739 $ (301 ) $ 438 $ — $ — $ 438 Derivatives (included in other assets) 82 — 82 (21 ) (5 ) 56 Total assets $ 821 $ (301 ) $ 520 $ (21 ) $ (5 ) $ 494 Liabilities: Federal funds and other short-term borrowings $ 5,245 $ (301 ) $ 4,944 $ — $ — $ 4,944 Derivatives (included in other liabilities) 25 — 25 (21 ) — 4 Total Liabilities $ 5,270 $ (301 ) $ 4,969 $ (21 ) $ — $ 4,948 December 31, 2018 (In millions) Gross amounts not offset in the balance sheet Description Gross amounts recognized Gross amounts offset in the balance sheet Net amounts presented in the balance sheet Financial instruments Cash collateral received/pledged Net amount Assets: Federal funds sold and security resell agreements $ 1,461 $ — $ 1,461 $ — $ — $ 1,461 Derivatives (included in other assets) 45 — 45 (35 ) (3 ) 7 Total assets $ 1506 $ — $ 1506 $ (35 ) $ (3 ) $ 1468 Liabilities: Federal funds and other short-term borrowings $ 5,653 $ — $ 5,653 $ — $ — $ 5,653 Derivatives (included in other liabilities) 39 — 39 (35 ) (1 ) 3 Total Liabilities $ 5,692 $ — $ 5,692 $ (35 ) $ (1 ) $ 5,656

Investment Securities (Tables)

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2019
Investments [Abstract]
Summary Of Investment Securities	March 31, 2019 (In millions) Amortized cost Gross unrealized gains Gross unrealized losses Estimated fair value Held-to-maturity Municipal securities $ 764 $ 4 $ 6 $ 762 Available-for-sale U.S. Treasury securities 40 — — 40 U.S. Government agencies and corporations: Agency securities 1,407 2 11 1,398 Agency guaranteed mortgage-backed securities 10,384 36 136 10,284 Small Business Administration loan-backed securities 1,919 1 43 1,877 Municipal securities 1,270 16 3 1,283 Other debt securities 25 — 3 22 Total available-for-sale 15,045 55 196 14,904 Total investment securities $ 15,809 $ 59 $ 202 $ 15,666 December 31, 2018 (In millions) Amortized Gross unrealized gains Gross unrealized losses Estimated Held-to-maturity Municipal securities $ 774 $ 4 $ 11 $ 767 Available-for-sale U.S. Treasury securities 40 — — 40 U.S. Government agencies and corporations: Agency securities 1,394 — 19 1,375 Agency guaranteed mortgage-backed securities 10,236 18 240 10,014 Small Business Administration loan-backed securities 2,042 1 47 1,996 Municipal securities 1,303 4 16 1,291 Other debt securities 25 — 4 21 Total available-for-sale debt securities 15,040 23 326 14,737 Total investment securities $ 15,814 $ 27 $ 337 $ 15,504
Contractual Maturities Debt Securities	March 31, 2019 Held-to-maturity Available-for-sale (In millions) Amortized cost Estimated fair value Amortized cost Estimated fair value Due in one year or less $ 252 $ 252 $ 2,147 $ 2,125 Due after one year through five years 329 328 5,984 5,928 Due after five years through ten years 132 132 4,441 4,406 Due after ten years 51 50 2,473 2,445 Total debt investment securities $ 764 $ 762 $ 15,045 $ 14,904
Summary Of Amount Of Gross Unrealized Losses For Debt Securities And Estimated Fair Value	March 31, 2019 Less than 12 months 12 months or more Total (In millions) Gross unrealized losses Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses Estimated fair value Held-to-maturity Municipal securities $ — $ 24 $ 6 $ 415 $ 6 $ 439 Available-for-sale U.S. Government agencies and corporations: Agency securities — 46 11 994 11 1,040 Agency guaranteed mortgage-backed securities 2 270 134 6,799 136 7,069 Small Business Administration loan-backed securities 13 876 30 898 43 1,774 Municipal securities — 40 3 458 3 498 Other — — 3 12 3 12 Total available-for-sale 15 1,232 181 9,161 196 10,393 Total investment securities $ 15 $ 1,256 $ 187 $ 9,576 $ 202 $ 10,832 December 31, 2018 Less than 12 months 12 months or more Total (In millions) Gross unrealized losses Estimated fair value Gross unrealized losses Estimated fair value Gross unrealized losses Estimated fair value Held-to-maturity Municipal securities $ 1 $ 86 $ 10 $ 438 $ 11 $ 524 Available-for-sale U.S. Government agencies and corporations: Agency securities 2 245 17 913 19 1,158 Agency guaranteed mortgage-backed securities 16 1,081 224 6,661 240 7,742 Small Business Administration loan-backed securities 19 1,180 28 711 47 1,891 Municipal securities 2 266 14 641 16 907 Other — — 4 11 4 11 Total available-for-sale 39 2,772 287 8,937 326 11,709 Total investment securities $ 40 $ 2,858 $ 297 $ 9,375 $ 337 $ 12,233
Gains And Losses, Including OTTI, Recognized In Statement Of Income	Three Months Ended March 31, 2019 2018 (In millions) Gross gains Gross losses Gross gains Gross losses Investment securities: Other noninterest-bearing investments $ 4 $ 3 $ 1 $ 1 Net gains 1 $ 1 $ — 1 Net gains were recognized in securities gains (losses), net in the statement of income.
Tax and Nontaxable Interest Income by Investment Type [Table Text Block]	Three Months Ended March 31, (In millions) 2019 2018 Taxable Nontaxable Total Taxable Nontaxable Total Investment securities: Held-to-maturity $ 2 $ 4 $ 6 $ 2 $ 4 $ 6 Available-for-sale 83 6 89 73 6 79 Trading — 1 1 — 1 1 Total securities $ 85 $ 11 $ 96 $ 75 $ 11 $ 86

Loans And Allowance For Credi_2

Loans And Allowance For Credit Losses (Tables)	3 Months Ended
	Mar. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investment of accuring and nonaccruing troubled debt restructuring [Text Block]	Three Months Ended Three Months Ended (In millions) Accruing Nonaccruing Total Accruing Nonaccruing Total Commercial: Commercial and industrial $ — $ 3 $ 3 $ — $ 1 $ 1 Owner-occupied — — — — 1 1 Total commercial — 3 3 — 2 2 Commercial real estate: Term — 2 2 — — — Total commercial real estate — 2 2 — — — Total $ — $ 5 $ 5 $ — $ 2 $ 2 Note: Total loans modified as TDRs during the 12 months previous to March 31, 2019 and 2018 were $73 million and $111 million , respectively.
allowance for loan losses by impairment [Table Text Block]	The ALLL and outstanding loan balances according to the Bank’s impairment method are summarized as follows: March 31, 2019 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses: Individually evaluated for impairment $ 6 $ 1 $ 2 $ 9 Collectively evaluated for impairment 322 112 54 488 Total $ 328 $ 113 $ 56 $ 497 Outstanding loan balances: Individually evaluated for impairment $ 148 $ 50 $ 70 $ 268 Collectively evaluated for impairment 24,450 11,480 11,408 47,338 Total $ 24,598 $ 11,530 $ 11,478 $ 47,606 December 31, 2018 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses: Individually evaluated for impairment $ 6 $ 1 $ 2 $ 9 Collectively evaluated for impairment 325 109 52 486 Total $ 331 $ 110 $ 54 $ 495 Outstanding loan balances: Individually evaluated for impairment $ 164 $ 55 $ 72 $ 291 Collectively evaluated for impairment 23,998 11,070 11,355 46,423 Total $ 24,162 $ 11,125 $ 11,427 $ 46,714
Summary Of Major Portfolio Segment And Specific Loan Class	(In millions) March 31, December 31, Loans held for sale $ 69 $ 93 Commercial: Commercial and industrial $ 14,758 $ 14,513 Leasing 312 327 Owner-occupied 7,754 7,661 Municipal 1,774 1,661 Total commercial 24,598 24,162 Commercial real estate: Construction and land development 2,343 2,186 Term 9,187 8,939 Total commercial real estate 11,530 11,125 Consumer: Home equity credit line 2,884 2,937 1-4 family residential 7,294 7,176 Construction and other consumer real estate 636 643 Bankcard and other revolving plans 489 491 Other 175 180 Total consumer 11,478 11,427 Total loans 1 $ 47,606 $ 46,714
Summary Of Changes in The Allowance For Credit Losses	Changes in the allowance for credit losses are summarized as follows: Three Months Ended March 31, 2019 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses Balance at beginning of period $ 331 $ 110 $ 54 $ 495 Provision for loan losses (1 ) 1 2 2 Deductions: Gross loan and lease charge-offs 8 1 3 12 Recoveries 6 3 3 12 Net loan and lease charge-offs (recoveries) 2 (2 ) — — Balance at end of period $ 328 $ 113 $ 56 $ 497 Reserve for unfunded lending commitments Balance at beginning of period $ 40 $ 17 $ — $ 57 Provision for unfunded lending commitments 2 — — 2 Balance at end of period $ 42 $ 17 $ — $ 59 Total allowance for credit losses at end of period Allowance for loan losses $ 328 $ 113 $ 56 $ 497 Reserve for unfunded lending commitments 42 17 — 59 Total allowance for credit losses $ 370 $ 130 $ 56 $ 556 Three Months Ended March 31, 2018 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses Balance at beginning of period $ 371 $ 103 $ 44 $ 518 Provision for loan losses (40 ) (1 ) 1 (40 ) Gross loan and lease charge-offs 20 — 6 26 Recoveries 18 2 1 21 Net loan and lease charge-offs (recoveries) 2 (2 ) 5 5 Balance at end of period $ 329 $ 104 $ 40 $ 473 Reserve for unfunded lending commitments Balance at beginning of period $ 48 $ 10 $ — $ 58 Provision for unfunded lending commitments (8 ) 1 — (7 ) Balance at end of period $ 40 $ 11 $ — $ 51 Total allowance for credit losses at end of period Allowance for loan losses $ 329 $ 104 $ 40 $ 473 Reserve for unfunded lending commitments 40 11 — 51 Total allowance for credit losses $ 369 $ 115 $ 40 $ 524 The ALLL and outstanding loan balances according to the Bank’s impairment method are summarized as follows: March 31, 2019 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses: Individually evaluated for impairment $ 6 $ 1 $ 2 $ 9 Collectively evaluated for impairment 322 112 54 488 Total $ 328 $ 113 $ 56 $ 497 Outstanding loan balances: Individually evaluated for impairment $ 148 $ 50 $ 70 $ 268 Collectively evaluated for impairment 24,450 11,480 11,408 47,338 Total $ 24,598 $ 11,530 $ 11,478 $ 47,606
Summary Of Nonaccrual Loans	Nonaccrual loans are summarized as follows: (In millions) March 31, December 31, Loans held for sale $ — $ 6 Commercial: Commercial and industrial $ 72 $ 82 Leasing 1 2 Owner-occupied 69 67 Municipal 1 1 Total commercial 143 152 Commercial real estate: Construction and land development 1 — Term 32 38 Total commercial real estate 33 38 Consumer: Home equity credit line 11 13 1-4 family residential 45 42 Construction and other consumer real estate 2 — Bankcard and other revolving plans — 1 Other — — Total consumer loans 58 56 Total $ 234 $ 246
Summary Of Past Due Loans (Accruing And Nonaccruing)	Past due loans (accruing and nonaccruing) are summarized as follows: March 31, 2019 (In millions) Current 30-89 days past due 90+ days past due Total past due Total loans Accruing loans 90+ days past due Nonaccrual loans that are current 1 Loans held for sale $ 69 $ — $ — $ — $ 69 $ — $ — Commercial: Commercial and industrial $ 14,646 $ 86 $ 26 $ 112 $ 14,758 $ 4 $ 43 Leasing 311 — 1 1 312 — 1 Owner-occupied 7,702 33 19 52 7,754 1 45 Municipal 1,774 — — — 1,774 — 1 Total commercial 24,433 119 46 165 24,598 5 90 Commercial real estate: Construction and land development 2,333 9 1 10 2,343 1 — Term 9,164 17 6 23 9,187 1 24 Total commercial real estate 11,497 26 7 33 11,530 2 24 Consumer: Home equity credit line 2,875 5 4 9 2,884 — 5 1-4 family residential 7,260 13 21 34 7,294 — 17 Construction and other consumer real estate 636 — — — 636 — 2 Bankcard and other revolving plans 485 3 1 4 489 1 — Other 174 1 — 1 175 — — Total consumer loans 11,430 22 26 48 11,478 1 24 Total $ 47,360 $ 167 $ 79 $ 246 $ 47,606 $ 8 $ 138 December 31, 2018 (In millions) Current 30-89 days past due 90+ days past due Total past due Total loans Accruing loans 90+ days past due Nonaccrual loans that are current 1 Loans held for sale $ 89 $ — $ 4 $ 4 $ 93 $ — $ 2 Commercial: Commercial and industrial $ 14,445 $ 37 $ 31 $ 68 $ 14,513 $ 4 $ 46 Leasing 325 1 1 2 327 — 1 Owner-occupied 7,621 23 17 40 7,661 3 48 Municipal 1,661 — — — 1,661 — 1 Total commercial 24,052 61 49 110 24,162 7 96 Commercial real estate: Construction and land development 2,185 1 — 1 2,186 — — Term 8,924 4 11 15 8,939 1 26 Total commercial real estate 11,109 5 11 16 11,125 1 26 Consumer: Home equity credit line 2,927 4 6 10 2,937 — 4 1-4 family residential 7,143 15 18 33 7,176 — 19 Construction and other consumer real estate 642 1 — 1 643 — — Bankcard and other revolving plans 487 2 2 4 491 2 — Other 179 1 — 1 180 — — Total consumer loans 11,378 23 26 49 11,427 2 23 Total $ 46,539 $ 89 $ 86 $ 175 $ 46,714 $ 10 $ 145 1 Represents nonaccrual loans that are not past due more than 30 days; however, full payment of principal and interest is still not expected.
Summary Of Outstanding Loan Balances (Accruing And Nonaccruing) Categorized By Credit Quality Indicators	March 31, 2019 (In millions) Pass Special Mention Sub- standard Doubtful Total loans Total allowance Commercial: Commercial and industrial $ 14,047 $ 389 $ 322 $ — $ 14,758 Leasing 299 10 3 — 312 Owner-occupied 7,448 82 224 — 7,754 Municipal 1,745 2 27 — 1,774 Total commercial 23,539 483 576 — 24,598 $ 328 Commercial real estate: Construction and land development 2,334 — 9 — 2,343 Term 9,080 34 73 — 9,187 Total commercial real estate 11,414 34 82 — 11,530 113 Consumer: Home equity credit line 2,868 — 16 — 2,884 1-4 family residential 7,245 — 49 — 7,294 Construction and other consumer real estate 633 — 3 — 636 Bankcard and other revolving plans 487 — 2 — 489 Other 174 — 1 — 175 Total consumer loans 11,407 — 71 — 11,478 56 Total $ 46,360 $ 517 $ 729 $ — $ 47,606 $ 497 December 31, 2018 (In millions) Pass Special Mention Sub- standard Doubtful Total loans Total allowance Commercial: Commercial and industrial $ 13,891 $ 322 $ 300 $ — $ 14,513 Leasing 313 10 4 — 327 Owner-occupied 7,369 72 220 — 7,661 Municipal 1,632 2 27 — 1,661 Total commercial 23,205 406 551 — 24,162 $ 331 Commercial real estate: Construction and land development 2,174 11 1 — 2,186 Term 8,853 10 76 — 8,939 Total commercial real estate 11,027 21 77 — 11,125 110 Consumer: Home equity credit line 2,920 — 17 — 2,937 1-4 family residential 7,129 — 47 — 7,176 Construction and other consumer real estate 641 — 2 — 643 Bankcard and other revolving plans 488 — 3 — 491 Other 179 — 1 — 180 Total consumer loans 11,357 — 70 — 11,427 54 Total $ 45,589 $ 427 $ 698 $ — $ 46,714 $ 495
Summary Of Information On Impaired Loans	March 31, 2019 (In millions) Unpaid principal balance Recorded investment Total recorded investment Related allowance with no allowance with allowance Commercial: Commercial and industrial $ 99 $ 35 $ 44 $ 79 $ 5 Owner-occupied 56 42 11 53 1 Municipal 1 1 — 1 — Total commercial 156 78 55 133 6 Commercial real estate: Construction and land development — — — — — Term 39 33 2 35 — Total commercial real estate 39 33 2 35 — Consumer: Home equity credit line 15 12 3 15 — 1-4 family residential 63 30 23 53 2 Construction and other consumer real estate 2 — 2 2 — Other — — — — — Total consumer loans 80 42 28 70 2 Total $ 275 $ 153 $ 85 $ 238 $ 8 December 31, 2018 (In millions) Unpaid principal balance Recorded investment Total recorded investment Related allowance with no allowance with allowance Commercial: Commercial and industrial $ 112 $ 52 $ 36 $ 88 $ 4 Owner-occupied 67 31 29 60 2 Municipal 1 1 — 1 — Total commercial 180 84 65 149 6 Commercial real estate: Construction and land development 1 — — — — Term 44 37 3 40 — Total commercial real estate 45 37 3 40 — Consumer: Home equity credit line 15 12 2 14 — 1-4 family residential 69 32 25 57 2 Construction and other consumer real estate 1 1 — 1 — Other — — — — — Total consumer loans 85 45 27 72 2 Total $ 310 $ 166 $ 95 $ 261 $ 8 Three Months Ended Three Months Ended (In millions) Average recorded investment Interest income recognized Average recorded investment Interest income recognized Commercial: Commercial and industrial $ 83 $ 1 $ 148 $ — Owner-occupied 60 — 91 8 Municipal 1 — 1 — Total commercial 144 1 240 8 Commercial real estate: Construction and land development — — 5 — Term 35 — 57 — Total commercial real estate 35 — 62 — Consumer: Home equity credit line 14 — 20 — 1-4 family residential 55 — 55 — Construction and other consumer real estate 2 — 2 — Other — — — — Total consumer loans 71 — 77 — Total $ 250 $ 1 $ 379 $ 8
Summary Of Selected Information On TDRs That Includes Recorded Investment On An Accruing And Nonaccruing Basis By Loan Class And Modification Type	March 31, 2019 Recorded investment resulting from the following modification types: (In millions) Interest rate below market Maturity or term extension Principal forgiveness Payment deferral Other 1 Multiple modification types 2 Total Accruing Commercial: Commercial and industrial $ 2 $ 4 $ — $ — $ 14 $ 6 $ 26 Owner-occupied 4 1 — — 3 7 15 Municipal — — — — — — — Total commercial 6 5 — — 17 13 41 Commercial real estate: Construction and land development — — — — — — — Term 1 2 — 1 — 5 9 Total commercial real estate 1 2 — 1 — 5 9 Consumer: Home equity credit line — 1 9 — — 2 12 1-4 family residential 1 1 6 1 1 25 35 Construction and other consumer real estate — 1 — — — — 1 Total consumer loans 1 3 15 1 1 27 48 Total accruing 8 10 15 2 18 45 98 Nonaccruing Commercial: Commercial and industrial 1 4 — 1 2 24 32 Owner-occupied 6 — — — 1 6 13 Municipal — — — — — 1 1 Total commercial 7 4 — 1 3 31 46 Commercial real estate: Term 3 — — 2 3 12 20 Total commercial real estate 3 — — 2 3 12 20 Consumer: Home equity credit line — — 1 — — — 1 1-4 family residential — — 1 — 1 7 9 Total consumer loans — — 2 — 1 7 10 Total nonaccruing 10 4 2 3 7 50 76 Total $ 18 $ 14 $ 17 $ 5 $ 25 $ 95 $ 174 1 Includes TDRs that resulted from other modification types including, but not limited to, a legal judgment awarded on different terms, a bankruptcy plan confirmed on different terms, a settlement that includes the delivery of collateral in exchange for debt reduction, etc. 2 Includes TDRs that resulted from a combination of any of the previous modification types. December 31, 2018 Recorded investment resulting from the following modification types: (In millions) Interest rate below market Maturity or term extension Principal forgiveness Payment deferral Other 1 Multiple modification types 2 Total Accruing Commercial: Commercial and industrial $ 2 $ 4 $ — $ — $ 15 $ 7 $ 28 Owner-occupied 3 2 — — 2 14 21 Total commercial 5 6 — — 17 21 49 Commercial real estate: Construction and land development — — — — — — — Term 2 2 — 1 — 6 11 Total commercial real estate 2 2 — 1 — 6 11 Consumer: Home equity credit line — 1 8 — — 3 12 1-4 family residential 1 2 6 1 1 28 39 Construction and other consumer real estate — — — — — 1 1 Total consumer loans 1 3 14 1 1 32 52 Total accruing 8 11 14 2 18 59 112 Nonaccruing Commercial: Commercial and industrial 1 6 — 1 10 27 45 Owner-occupied 6 — — 1 2 5 14 Municipal — — — — — 1 1 Total commercial 7 6 — 2 12 33 60 Commercial real estate: Term 3 — — 2 14 1 20 Total commercial real estate 3 — — 2 14 1 20 Consumer: Home equity credit line — — 1 — — — 1 1-4 family residential — — 1 — 1 7 9 Total consumer loans — — 2 — 1 7 10 Total nonaccruing 10 6 2 4 27 41 90 Total $ 18 $ 17 $ 16 $ 6 $ 45 $ 100 $ 202 1 Includes TDRs that resulted from other modification types including, but not limited to, a legal judgment awarded on different terms, a bankruptcy plan confirmed on different terms, a settlement that includes the delivery of collateral in exchange for debt reduction, etc. 2 Includes TDRs that resulted from a combination of any of the previous modification types.

Derivative Instruments And He_2

Derivative Instruments And Hedging Activities Derivative Instruments and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Schedule of Derivative Instruments	March 31, 2019 December 31, 2018 Notional amount Fair value Notional amount Fair value (In millions) Other assets Other liabilities Other assets Other liabilities Derivatives designated as hedging instruments: Cash flow hedges: Purchased interest rate floors $ 3,000 $ 9 $ — $ — $ — $ — Received-fixed interest rate swaps 1,338 — — 687 — — Fair value hedges: Received-fixed interest rate swaps 1,000 — — 500 — — Total derivatives designated as hedging instruments 5,338 9 — 1,187 — — Derivatives not designated as hedging instruments: Customer-facing interest rate derivatives 3,035 69 22 2,826 40 36 Offsetting interest rate derivatives 3,035 — — 2,826 — — Other interest rate derivatives 449 1 1 253 1 1 Foreign exchange derivatives 367 3 2 389 4 2 Total derivatives not designated as hedging instruments 6,886 73 25 6,294 45 39 Total derivatives $ 12,224 $ 82 $ 25 $ 7,481 $ 45 $ 39 Amount of derivative gain (loss) recognized/reclassified Three Months Ended March 31, 2019 Three Months Ended March 31, 2018 (In millions) OCI Reclassified from AOCI to interest income Noninterest income (expense) Offset to interest expense OCI Reclassified from AOCI to interest income Noninterest Offset to Derivatives designated as hedging instruments: Cash flow hedges of floating-rate assets 1 : Purchased interest rate floors $ 3 $ — $ (5 ) $ — Interest rate swaps 8 2 Fair value hedges of fixed-rate debt: Receive-fixed interest rate swaps $ — $ — Total derivatives designated as hedging instruments 11 2 — (5 ) — — Derivatives not designated as hedging instruments: Customer-facing interest rate derivatives $ (41 ) $ 45 Offsetting interest rate derivatives 44 (38 ) Other interest rate derivatives — (2 ) Foreign exchange derivatives 5 5 Total derivatives not designated as hedging instruments 8 10 Total derivatives $ 11 $ 2 $ 8 $ — $ (5 ) $ — $ 10 $ —
Schedule Of Gain (Loss) Of Derivative Instruments	Gain/(loss) recorded in income Three Months Ended March 31, 2019 Three Months Ended March 31, 2018 (In millions) Derivatives 2 Hedged items Total income statement impact Derivatives 2 Hedged items Total income statement impact Interest rate swaps 1 $ 6 $ (6 ) $ — $ — $ — $ — 1 Consists of hedges of benchmark interest rate risk of fixed-rate long-term debt. Gains and losses were recorded in net interest income. 2 The income for the derivative does not reflect interest income/expense to be consistent with the presentation of the gains/ (losses) on the hedged items. Amount of derivative gain (loss) recognized/reclassified Three Months Ended March 31, 2019 Three Months Ended March 31, 2018 (In millions) OCI Reclassified from AOCI to interest income Noninterest income (expense) Offset to interest expense OCI Reclassified from AOCI to interest income Noninterest Offset to Derivatives designated as hedging instruments: Cash flow hedges of floating-rate assets 1 : Purchased interest rate floors $ 3 $ — $ (5 ) $ — Interest rate swaps 8 2 Fair value hedges of fixed-rate debt: Receive-fixed interest rate swaps $ — $ — Total derivatives designated as hedging instruments 11 2 — (5 ) — — Derivatives not designated as hedging instruments: Customer-facing interest rate derivatives $ (41 ) $ 45 Offsetting interest rate derivatives 44 (38 ) Other interest rate derivatives — (2 ) Foreign exchange derivatives 5 5 Total derivatives not designated as hedging instruments 8 10 Total derivatives $ 11 $ 2 $ 8 $ — $ (5 ) $ — $ 10 $ — Note: These schedules are not intended to present at any given time the Bank’s long/short position with respect to its derivative contracts. 1 Amounts recognized in OCI and reclassified from AOCI represent the effective portion of the derivative gain (loss). For the 12 months following March 31, 2019 , we estimate that $(7) million will be reclassified from AOCI into interest income

Derivative Instruments And He_3

Derivative Instruments And Hedging Activities Long-term debt derivative (Tables)	3 Months Ended
	Mar. 31, 2019
Derivatives, Fair Value [Line Items]
Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]	Carrying amount of the hedged assets/(liabilities) Cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged assets/(liabilities) (In millions) March 31, 2019 December 31, 2018 March 31, 2019 December 31, 2018 Long-term debt $ (1,010 ) $ (505 ) $ (10 ) $ (5 )

Leases Lease Expense (Tables)

Leases Lease Expense (Tables)	3 Months Ended
	Mar. 31, 2019
Leases Expense [Abstract]
Lease, Cost [Table Text Block]	(In millions) Three Months Ended March 31, 2019 Operating lease costs $ 12 Variable lease costs 13 Total lease cost $ 25
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]	(In millions) Three Months Ended March 31, 2019 Cash paid for amounts in the measurement of lease liabilities: Operating cash disbursements from operating leases $ 10
Finance Lease, Liability, Maturity [Table Text Block]	(In millions) 2019 1 $ 41 2020 45 2021 39 2022 35 2023 31 Thereafter 114 Total $ 305 1 Contractual maturities for the nine months remaining in 2019.

Debt And Shareholders' Equity (

Debt And Shareholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Schedule of Long-term Debt Instruments [Table Text Block]	Long-term debt is summarized as follows: (In millions) March 31, December 31, 2018 Subordinated notes $ 87 $ 87 Senior notes 1,141 637 Total $ 1,228 $ 724
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]	Amounts reclassified from AOCI 1 Statement of income (SI) Balance sheet (BS) (In millions) Three Months Ended Details about AOCI components 2019 2018 Affected line item Net unrealized losses on derivative instruments $ (1 ) $ — SI Interest and fees on loans Income tax benefit — — Amounts Reclassified from AOCI $ (1 ) $ — 1 Negative reclassification amounts indicate decreases to earnings in the statement of income and increases to balance sheet assets.
Schedule Of Changes In Accumulated Other Comprehensive Income (Loss)	(In millions) Net unrealized gains (losses) on investment securities Net unrealized gains (losses) on derivatives and other Pension and post-retirement Total Three Months Ended March 31, 2019 Balance at December 31, 2018 $ (228 ) $ (1 ) $ (21 ) $ (250 ) OCI before reclassifications, net of tax 122 5 — 127 Amounts reclassified from AOCI, net of tax — 1 — 1 OCI 122 6 — 128 Balance at March 31, 2019 $ (106 ) $ 5 $ (21 ) $ (122 ) Income tax expense included in OCI $ 40 $ 2 $ — $ 42 Three Months Ended March 31, 2018 Balance at December 31, 2017 $ (114 ) $ (2 ) $ (23 ) $ (139 ) OCI (loss) before reclassifications, net of tax (126 ) (2 ) — (128 ) Amounts reclassified from AOCI, net of tax — — — — OCI (loss) (126 ) (2 ) — (128 ) Balance at March 31, 2018 $ (240 ) $ (4 ) $ (23 ) $ (267 ) Income tax benefit included in OCI $ (41 ) $ (1 ) $ — $ (42 )

Commitments, Guarantees, And _2

Commitments, Guarantees, And Contingent Liabilities (Tables)	3 Months Ended
	Mar. 31, 2019
Guarantees, Commitments And Contingencies [Abstract]
Schedule Of Guarantees Issued	(In millions) March 31, December 31, Net unfunded commitments to extend credit 1 $ 21,632 $ 21,454 Standby letters of credit: Financial 544 655 Performance 196 199 Commercial letters of credit 27 18 Total unfunded lending commitments $ 22,399 $ 22,326 1 Net of participations

Revenue Recognition Revenue R_2

Revenue Recognition Revenue Recognition (Tables)	3 Months Ended
	Mar. 31, 2019
Revenue Recognition and Deferred Revenue [Abstract]
Revenue Recognition, Services, Commissions [Policy Text Block]	Three Months Ended (In millions) 2019 2018 Card fee income $ 34 $ 33 ATM fees 2 2 Other service charges 3 4 Other commissions and fees 4 5 Total $ 43 $ 44
Reconciliation of Revenue from Segments to Consolidated [Table Text Block]	Zions Bank Amegy CB&T (In millions) 2019 2018 2019 2018 2019 2018 Service charges and fees on deposit accounts $ 13 $ 15 $ 11 $ 10 $ 7 $ 7 Other service charges, commissions, and fees 17 16 9 8 7 5 Wealth management and trust income 4 4 3 2 1 1 Capital markets and foreign exchange 1 1 (1 ) (2 ) 1 1 Total noninterest income from contracts with customers (ASC 606) 35 36 22 18 16 14 Other noninterest income (Non-ASC 606 customer related) (3 ) (2 ) 13 12 4 4 Total customer-related fees 32 34 35 30 20 18 Other noninterest income (non-customer related) 1 1 (1 ) 2 (1 ) 3 Total noninterest income 33 35 34 32 19 21 Other real estate owned gain from sale 1 1 — — — — Net interest income 180 167 131 127 138 131 Total income less interest expense $ 214 $ 203 $ 165 $ 159 $ 157 $ 152 NBAZ NSB Vectra (In millions) 2019 2018 2019 2018 2019 2018 Service charges and fees on deposit accounts $ 3 $ 3 $ 4 $ 4 $ 2 $ 2 Other service charges, commissions, and fees 3 2 3 3 2 3 Wealth management and trust income — 1 1 1 — — Capital markets and foreign exchange — — — — — — Total noninterest income from contracts with customers (ASC 606) 6 6 8 8 4 5 Other noninterest income (Non-ASC 606 customer related) 3 2 2 2 1 1 Total customer-related fees 9 8 10 10 5 6 Other noninterest income (non-customer related) 1 1 — — 1 — Total noninterest income 10 9 10 10 6 6 Other real estate owned gain from sale — — — — — — Net interest income 60 53 40 35 36 32 Total income less interest expense $ 70 $ 62 $ 50 $ 45 $ 42 $ 38 TCBW Other Consolidated Bank (In millions) 2019 2018 2019 2018 2019 2018 Service charges and fees on deposit accounts $ — $ — $ — $ 1 $ 40 $ 42 Other service charges, commissions, and fees 1 1 1 6 43 44 Wealth management and trust income — — 4 3 13 12 Capital markets and foreign exchange — — 2 3 3 3 Total noninterest income from contracts with customers (ASC 606) 1 1 7 13 99 101 Other noninterest income (Non-ASC 606 customer related) — — 1 3 21 22 Total customer-related fees 1 1 8 16 120 123 Other noninterest income (non-customer related) — — 11 8 12 15 Total noninterest income 1 1 19 24 132 138 Other real estate owned gain from sale — — — — 1 1 Net interest income 14 11 (23 ) (14 ) 576 542 Total income less interest expense $ 15 $ 12 $ (4 ) $ 10 $ 709 $ 681

Retirement Plans (Tables)

Retirement Plans (Tables)	3 Months Ended
	Mar. 31, 2019
Defined Benefit Plan [Abstract]
Schedule Of Net Periodic Benefit Cost (Credit) For Pension And Postretirement Plans	(In millions) Three Months Ended March 31, 2019 2018 Interest cost $ 1 $ 1 Expected return on plan assets (2 ) (3 ) Partial settlement loss — 1 Amortization of net actuarial loss 1 — Net periodic benefit cost (benefit) $ — $ (1 )

Net Earnings per Common Share B

Net Earnings per Common Share Basic and diluted net earnings per common share (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table Text Block]	Three Months Ended (In millions, except shares and per share amounts) 2019 2018 Basic: Net income $ 213 $ 238 Less common and preferred dividends 64 47 Undistributed earnings 149 191 Less undistributed earnings applicable to nonvested shares 1 1 Undistributed earnings applicable to common shares 148 190 Distributed earnings applicable to common shares 56 39 Total earnings applicable to common shares $ 204 $ 229 Weighted average common shares outstanding (in thousands) 184,767 196,722 Net earnings per common share $ 1.10 $ 1.16 Diluted: Total earnings applicable to common shares $ 204 $ 229 Weighted average common shares outstanding (in thousands) 184,767 196,722 Dilutive effect of common stock warrants (in thousands) 9,739 12,382 Dilutive effect of stock options (in thousands) 735 1,139 Weighted average diluted common shares outstanding (in thousands) 195,241 210,243 Net earnings per common share $ 1.04 $ 1.09

Net Earnings per Common Share W

Net Earnings per Common Share Weighted average shares of stock awards that were anti-dilutive (Tables)	3 Months Ended
	Mar. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Schedule of Weighted Average Number of Shares [Table Text Block]	Three Months Ended (In thousands) 2019 2018 Restricted stock and restricted stock units 1,423 1,757

Operating Segment Information (

Operating Segment Information (Tables)	3 Months Ended
	Mar. 31, 2019
Segment Reporting Information [Line Items]
Operating Segment Information	OPERATING SEGMENT INFORMATION We manage our operations and prepare management reports and other information with a primary focus on geographical area. Our banking operations are managed under their own individual brand names, including Zions Bank, Amegy Bank, California Bank & Trust, National Bank of Arizona, Nevada State Bank, Vectra Bank Colorado, and The Commerce Bank of Washington. Performance assessment and resource allocation are based upon this geographical structure. We use an internal funds transfer pricing (“FTP”) allocation system to report results of operations for business segments. This process is continually refined. Total average loans and deposits presented for the banking segments include insignificant intercompany amounts between banking segments and may also include deposits with the Other segment. As of March 31, 2019 , our banking business is conducted through 7 locally managed and branded segments in distinct geographical areas. Zions Bank operates 98 branches in Utah, 23 branches in Idaho, and one branch in Wyoming. Amegy operates 74 branches in Texas. CB&T operates 90 branches in California. NBAZ operates 58 branches in Arizona. NSB operates 50 branches in Nevada. Vectra operates 36 branches in Colorado and one branch in New Mexico. TCBW operates one branch in Washington and one branch in Oregon. The operating segment identified as “Other” includes certain nonbank financial service subsidiaries, centralized back-office functions, and eliminations of transactions between segments. The major components of net interest income at the Bank’s back-office include the revenue associated with the investments securities portfolio and the offset of the FTP costs and benefits provided to the business segments. The following schedule does not present total assets or income tax expense for each operating segment, but instead presents average loans, average deposits and income before income taxes because these are the metrics that management uses when evaluating performance and making decisions pertaining to the operating segments. The Bank’s net interest income includes interest expense on borrowed funds. The condensed statement of income identifies the components of income and expense which affect the operating amounts presented in the Other segment. The accounting policies of the individual operating segments are the same as those of the Bank. Transactions between operating segments are primarily conducted at fair value, resulting in profits that are eliminated for reporting consolidated results of operations. The following schedule presents selected operating segment information for the three months ended March 31, 2019 and 2018 : (In millions) Zions Bank Amegy CB&T 2019 2018 2019 2018 2019 2018 SELECTED INCOME STATEMENT DATA Net interest income $ 180 $ 167 $ 131 $ 127 $ 138 $ 131 Provision for credit losses 11 (2 ) (15 ) (53 ) 3 2 Net interest income after provision for loan losses 169 169 146 180 135 129 Noninterest income 33 35 34 32 19 21 Noninterest expense 118 113 88 87 82 77 Income (loss) before income taxes $ 84 $ 91 $ 92 $ 125 $ 72 $ 73 SELECTED AVERAGE BALANCE SHEET DATA Total average loans $ 12,939 $ 12,453 $ 11,861 $ 11,370 $ 10,574 $ 9,929 Total average deposits 15,524 15,712 11,441 10,816 11,243 11,119 (In millions) NBAZ NSB Vectra 2019 2018 2019 2018 2019 2018 SELECTED INCOME STATEMENT DATA Net interest income $ 60 $ 53 $ 40 $ 35 $ 36 $ 32 Provision for credit losses 3 2 (1 ) — 4 3 Net interest income after provision for loan losses 57 51 41 35 32 29 Noninterest income 10 9 10 10 6 6 Noninterest expense 39 38 36 36 28 27 Income (loss) before income taxes $ 28 $ 22 $ 15 $ 9 $ 10 $ 8 SELECTED AVERAGE BALANCE SHEET DATA Total average loans $ 4,749 $ 4,543 $ 2,500 $ 2,348 $ 3,055 $ 2,794 Total average deposits 4,894 4,783 4,329 4,223 2,821 2,711 (In millions) TCBW Other Consolidated Bank 2019 2018 2019 2018 2019 2018 SELECTED INCOME STATEMENT DATA Net interest income $ 14 $ 11 $ (23 ) $ (14 ) $ 576 $ 542 Provision for credit losses — 1 (1 ) — 4 (47 ) Net interest income after provision for loan losses 14 10 (22 ) (14 ) 572 589 Noninterest income 1 1 19 24 132 138 Noninterest expense 6 6 33 35 430 419 Income (loss) before income taxes $ 9 $ 5 $ (36 ) $ (25 ) $ 274 $ 308 SELECTED AVERAGE BALANCE SHEET DATA Total average loans $ 1,110 $ 1,084 $ 383 $ 343 $ 47,171 $ 44,864 Total average deposits 1,075 1,073 2,589 1,557 53,916 51,994
Schedule of Segment Reporting Information, by Segment	(In millions) Zions Bank Amegy CB&T 2019 2018 2019 2018 2019 2018 SELECTED INCOME STATEMENT DATA Net interest income $ 180 $ 167 $ 131 $ 127 $ 138 $ 131 Provision for credit losses 11 (2 ) (15 ) (53 ) 3 2 Net interest income after provision for loan losses 169 169 146 180 135 129 Noninterest income 33 35 34 32 19 21 Noninterest expense 118 113 88 87 82 77 Income (loss) before income taxes $ 84 $ 91 $ 92 $ 125 $ 72 $ 73 SELECTED AVERAGE BALANCE SHEET DATA Total average loans $ 12,939 $ 12,453 $ 11,861 $ 11,370 $ 10,574 $ 9,929 Total average deposits 15,524 15,712 11,441 10,816 11,243 11,119 (In millions) NBAZ NSB Vectra 2019 2018 2019 2018 2019 2018 SELECTED INCOME STATEMENT DATA Net interest income $ 60 $ 53 $ 40 $ 35 $ 36 $ 32 Provision for credit losses 3 2 (1 ) — 4 3 Net interest income after provision for loan losses 57 51 41 35 32 29 Noninterest income 10 9 10 10 6 6 Noninterest expense 39 38 36 36 28 27 Income (loss) before income taxes $ 28 $ 22 $ 15 $ 9 $ 10 $ 8 SELECTED AVERAGE BALANCE SHEET DATA Total average loans $ 4,749 $ 4,543 $ 2,500 $ 2,348 $ 3,055 $ 2,794 Total average deposits 4,894 4,783 4,329 4,223 2,821 2,711 (In millions) TCBW Other Consolidated Bank 2019 2018 2019 2018 2019 2018 SELECTED INCOME STATEMENT DATA Net interest income $ 14 $ 11 $ (23 ) $ (14 ) $ 576 $ 542 Provision for credit losses — 1 (1 ) — 4 (47 ) Net interest income after provision for loan losses 14 10 (22 ) (14 ) 572 589 Noninterest income 1 1 19 24 132 138 Noninterest expense 6 6 33 35 430 419 Income (loss) before income taxes $ 9 $ 5 $ (36 ) $ (25 ) $ 274 $ 308 SELECTED AVERAGE BALANCE SHEET DATA Total average loans $ 1,110 $ 1,084 $ 383 $ 343 $ 47,171 $ 44,864 Total average deposits 1,075 1,073 2,589 1,557 53,916 51,994

Basis of Presentaion (Details)

Basis of Presentaion (Details)	Mar. 31, 2019States
Basis Of Presentation [Abstract]
Number of States in which Entity Operates	11
Number of community regional banks operating in distinct geographical areas	7

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Derivatives, Fair Value [Line Items]
Other Liabilities, Fair Value Disclosure	$ 107,000,000	$ 95,000,000
Other Assets, Fair Value Disclosure	107,000,000	95,000,000
Derivative Credit Risk Valuation Adjustment, Derivative Liabilities	1,000,000		$ 1,000,000
Other noninterest-bearing investments valued under the cost method	10,000,000	10,000,000
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	272,000,000	329,000,000
Fair value of AFS securities	14,904,000,000	14,737,000,000
Principal amount of other real estate owned property sold	1,000,000
Equity Method Investments, Fair Value Disclosure	36,000,000	35,000,000
Fair Value, Inputs, Level 1 [Member]
Derivatives, Fair Value [Line Items]
Other Assets, Fair Value Disclosure		95,000,000
Fair value of AFS securities	40,000,000	40,000,000
Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair value of AFS securities	14,864,000,000	14,697,000,000
Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Fair value of AFS securities	0	0
Third Party Pricing Service [Member] | Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair value of AFS securities	0.94	0.95
Interest Rate Swaps For Customers [Member]
Derivatives, Fair Value [Line Items]
Other Liabilities, Fair Value Disclosure	22,000,000	36,000,000
Other Assets, Fair Value Disclosure	69,000,000	40,000,000
Interest Rate Swaps For Customers [Member] | Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Other Liabilities, Fair Value Disclosure	22,000,000	36,000,000
Other Assets, Fair Value Disclosure	69,000,000	40,000,000
Warranty, Rights and Obligations, Fair Value Option [Member] | Fair Value, Inputs, Level 1 [Member]
Derivatives, Fair Value [Line Items]
Other Liabilities, Fair Value Disclosure	107,000,000	95,000,000
Other Assets, Fair Value Disclosure	107,000,000
Available-for-sale Securities [Member]
Derivatives, Fair Value [Line Items]
Fair value of AFS securities	1,283,000,000	1,291,000,000
Available-for-sale Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair value of AFS securities	1,283,000,000	1,291,000,000
Available-for-sale Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Fair value of AFS securities
Other Real Estate Owned Properties [Member]
Derivatives, Fair Value [Line Items]
Net gains on sale of OREO properties	1,000,000
Derivative [Member]
Derivatives, Fair Value [Line Items]
Other Liabilities, Fair Value Disclosure	1,000,000	1,000,000
Other Assets, Fair Value Disclosure	1,000,000	1,000,000
Derivative [Member] | Fair Value, Inputs, Level 1 [Member]
Derivatives, Fair Value [Line Items]
Other Liabilities, Fair Value Disclosure	2,000,000	2,000,000
Other Assets, Fair Value Disclosure	$ 3,000,000	4,000,000
Derivative [Member] | Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Other Liabilities, Fair Value Disclosure		$ 1,000,000

Fair Value (Schedule Of Assets

Fair Value (Schedule Of Assets And Liabilities Measured At Fair Value By Class On A Recurring Basis) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	$ 14,904,000,000	$ 14,737,000,000
Debt Securities, Trading, and Equity Securities, FV-NI	316,000,000	106,000,000
Other Assets, Fair Value Disclosure	107,000,000	95,000,000
Assets, Fair Value Disclosure	16,051,000,000	15,619,000,000
Financial Instruments Sold, Not yet Purchased, at Fair Value	52,000,000	85,000,000
Other Liabilities, Fair Value Disclosure	107,000,000	95,000,000
Financial and Nonfinancial Liabilities, Fair Value Disclosure	184,000,000	219,000,000
Principal amount of other real estate owned property sold	1,000,000
Other noninterest-bearing investments valued under the cost method	10,000,000	10,000,000
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	272,000,000	329,000,000
Equity Method Investments, Fair Value Disclosure	36,000,000	35,000,000
Other Real Estate Owned Properties [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gains (Losses) on Sales of Other Real Estate	1,000,000
US Treasury Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	13,599,000,000	13,425,000,000
Asset-backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	22,000,000	21,000,000
Interest Rate Swaps For Customers [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	69,000,000	40,000,000
Other Liabilities, Fair Value Disclosure	22,000,000	36,000,000
Available-for-sale Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	1,283,000,000	1,291,000,000
Derivative [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	1,000,000	1,000,000
Other Liabilities, Fair Value Disclosure	1,000,000	1,000,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	311,000,000	153,000,000
Financial and Nonfinancial Liabilities, Fair Value Disclosure	161,000,000	182,000,000
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	15,616,000,000	15,346,000,000
Financial and Nonfinancial Liabilities, Fair Value Disclosure	23,000,000	37,000,000
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	124,000,000	120,000,000
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0	0
Bank-owned life insurance [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure	518,000,000	516,000,000
Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure	107,000,000	102,000,000
Assets, Fair Value Disclosure	0	1,000,000
Interest-Only-Strip [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	17,000,000	18,000,000
Designated as Hedging Instrument [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	9,000,000
Foreign Exchange Contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	3,000,000	4,000,000
Other Liabilities, Fair Value Disclosure	2,000,000	2,000,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	40,000,000	40,000,000
Debt Securities, Trading, and Equity Securities, FV-NI	161,000,000	14,000,000
Other Assets, Fair Value Disclosure		95,000,000
Financial Instruments Sold, Not yet Purchased, at Fair Value	52,000,000	85,000,000
Fair Value, Inputs, Level 1 [Member] | Warranty, Rights and Obligations, Fair Value Option [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	107,000,000
Other Liabilities, Fair Value Disclosure	107,000,000	95,000,000
Fair Value, Inputs, Level 1 [Member] | US Treasury Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	40,000,000	40,000,000
Fair Value, Inputs, Level 1 [Member] | Derivative [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	3,000,000	4,000,000
Other Liabilities, Fair Value Disclosure	2,000,000	2,000,000
Fair Value, Inputs, Level 1 [Member] | Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	14,864,000,000	14,697,000,000
Debt Securities, Trading, and Equity Securities, FV-NI	155,000,000	92,000,000
Financial Instruments Sold, Not yet Purchased, at Fair Value	0	0
Fair Value, Inputs, Level 2 [Member] | US Treasury Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	13,559,000,000	13,385,000,000
Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	22,000,000	21,000,000
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swaps For Customers [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	69,000,000	40,000,000
Other Liabilities, Fair Value Disclosure	22,000,000	36,000,000
Fair Value, Inputs, Level 2 [Member] | Derivative Interest Rate Related And Other [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	1,000,000	1,000,000
Other Liabilities, Fair Value Disclosure	1,000,000
Fair Value, Inputs, Level 2 [Member] | Available-for-sale Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	1,283,000,000	1,291,000,000
Fair Value, Inputs, Level 2 [Member] | Derivative [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Liabilities, Fair Value Disclosure		1,000,000
Fair Value, Inputs, Level 2 [Member] | Bank-owned life insurance [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure	518,000,000	516,000,000
Fair Value, Inputs, Level 2 [Member] | Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member] | Designated as Hedging Instrument [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	9,000,000
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	0	0
Financial Instruments Sold, Not yet Purchased, at Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | US Treasury Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure
Fair Value, Inputs, Level 3 [Member] | Available-for-sale Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure
Fair Value, Inputs, Level 3 [Member] | Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure	107,000,000	102,000,000
Assets, Fair Value Disclosure	0	1,000,000
Fair Value, Inputs, Level 3 [Member] | Interest-Only-Strip [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	17,000,000	18,000,000
Third Party Pricing Service [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	$ 0.94	$ 0.95

Fair Value (Schedule Of Key Mod

Fair Value (Schedule Of Key Model Inputs And Assumptions Used To Fair Value Certain Asset-Backed Securities) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Investments, Fair Value Disclosure	$ 14,904	$ 14,737
Debt Securities, Trading, and Equity Securities, FV-NI	316	106
Other Assets, Fair Value Disclosure	107	95
Assets, Fair Value Disclosure	16,051	15,619
Financial Instruments Sold, Not yet Purchased, at Fair Value	52	85
Other Liabilities, Fair Value Disclosure	107	95
Financial and Nonfinancial Liabilities, Fair Value Disclosure	184	219
Designated as Hedging Instrument [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Assets, Fair Value Disclosure	9
US Treasury Securities [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Investments, Fair Value Disclosure	13,599	13,425
Interest Rate Swaps For Customers [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Assets, Fair Value Disclosure	69	40
Other Liabilities, Fair Value Disclosure	22	36
Fair Value, Inputs, Level 1 [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Assets, Fair Value Disclosure	311	153
Financial and Nonfinancial Liabilities, Fair Value Disclosure	161	182
Fair Value, Inputs, Level 2 [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Assets, Fair Value Disclosure	15,616	15,346
Financial and Nonfinancial Liabilities, Fair Value Disclosure	23	37
Fair Value, Inputs, Level 3 [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Assets, Fair Value Disclosure	124	120
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0	0
Foreign Exchange Contract [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Assets, Fair Value Disclosure	3	4
Other Liabilities, Fair Value Disclosure	2	2
Interest-Only-Strip [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Assets, Fair Value Disclosure	17	18
Private Equity Funds [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure	107	102
Assets, Fair Value Disclosure	0	1
Bank-owned life insurance [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure	518	516
Available-for-sale Securities [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Investments, Fair Value Disclosure	1,283	1,291
Derivative [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Assets, Fair Value Disclosure	1	1
Other Liabilities, Fair Value Disclosure	1	1
Asset-backed Securities [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Investments, Fair Value Disclosure	22	21
Fair Value, Inputs, Level 1 [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Investments, Fair Value Disclosure	40	40
Debt Securities, Trading, and Equity Securities, FV-NI	161	14
Other Assets, Fair Value Disclosure		95
Financial Instruments Sold, Not yet Purchased, at Fair Value	52	85
Fair Value, Inputs, Level 1 [Member] | US Treasury Securities [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Investments, Fair Value Disclosure	40	40
Fair Value, Inputs, Level 1 [Member] | Private Equity Funds [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 [Member] | Derivative [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Assets, Fair Value Disclosure	3	4
Other Liabilities, Fair Value Disclosure	2	2
Fair Value, Inputs, Level 2 [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Investments, Fair Value Disclosure	14,864	14,697
Debt Securities, Trading, and Equity Securities, FV-NI	155	92
Financial Instruments Sold, Not yet Purchased, at Fair Value	0	0
Fair Value, Inputs, Level 2 [Member] | Designated as Hedging Instrument [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Assets, Fair Value Disclosure	9
Fair Value, Inputs, Level 2 [Member] | US Treasury Securities [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Investments, Fair Value Disclosure	13,559	13,385
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swaps For Customers [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Assets, Fair Value Disclosure	69	40
Other Liabilities, Fair Value Disclosure	22	36
Fair Value, Inputs, Level 2 [Member] | Private Equity Funds [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member] | Bank-owned life insurance [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure	518	516
Fair Value, Inputs, Level 2 [Member] | Available-for-sale Securities [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Investments, Fair Value Disclosure	1,283	1,291
Fair Value, Inputs, Level 2 [Member] | Derivative [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Liabilities, Fair Value Disclosure		1
Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Investments, Fair Value Disclosure	22	21
Fair Value, Inputs, Level 3 [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Investments, Fair Value Disclosure	0	0
Financial Instruments Sold, Not yet Purchased, at Fair Value	0	0
Fair Value, Inputs, Level 3 [Member] | US Treasury Securities [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member] | Interest-Only-Strip [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Assets, Fair Value Disclosure	17	18
Fair Value, Inputs, Level 3 [Member] | Private Equity Funds [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure	107	102
Assets, Fair Value Disclosure	0	1
Fair Value, Inputs, Level 3 [Member] | Available-for-sale Securities [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Investments, Fair Value Disclosure
Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Investments, Fair Value Disclosure

Fair Value (Schedule Of Asset_2

Fair Value (Schedule Of Assets And Liabilities Measured At Fair Value By Class On A Recurring Basis Using Level 3 Inputs) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	$ 107		$ 95
Other Liabilities, Fair Value Disclosure	107		95
Private Equity Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets, Beginning balance	102	$ 95
Fair Value, Assets Measured On Recurring Basis, And Gain (Loss) Included In Equity Securities Gains (Losses), Net	1	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Noninterest Income	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	4	5
Fair value of assets, Ending balance	107	100
Servicing Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets, Beginning balance	18	18
Fair Value, Assets Measured On Recurring Basis, And Gain (Loss) Included In Equity Securities Gains (Losses), Net	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Noninterest Income	(1)	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	0	0
Fair value of assets, Ending balance	$ 17	$ 18
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure			$ 95

Fair Value (Schedule Of Realize

Fair Value (Schedule Of Realized Gains (Losses) Using Level 3 Inputs) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	$ 16,051		$ 15,619
Other Assets, Fair Value Disclosure	107		95
Other Liabilities, Fair Value Disclosure	107		95
Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	107	$ 100	102	$ 95
Fair Value, Assets Measured On Recurring Basis, And Gain (Loss) Included In Equity Securities Gains (Losses), Net	1	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	4	5
Servicing Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	17	18	18	$ 18
Fair Value, Assets Measured On Recurring Basis, And Gain (Loss) Included In Equity Securities Gains (Losses), Net	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	0	$ 0
Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	2		32
Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		1
Other Real Estate Owned [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	1		0
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	3		33
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure			95
Fair Value, Inputs, Level 1 [Member] | Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		0
Fair Value, Inputs, Level 1 [Member] | Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		0
Fair Value, Inputs, Level 1 [Member] | Other Real Estate Owned [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		0
Fair Value, Inputs, Level 2 [Member] | Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	2		32
Fair Value, Inputs, Level 2 [Member] | Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		0
Fair Value, Inputs, Level 2 [Member] | Other Real Estate Owned [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	1		0
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	3		32
Fair Value, Inputs, Level 3 [Member] | Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		0
Fair Value, Inputs, Level 3 [Member] | Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		1
Fair Value, Inputs, Level 3 [Member] | Other Real Estate Owned [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	0		0
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	$ 0		$ 1

Fair Value (Schedule Of Asset_3

Fair Value (Schedule Of Assets With Fair Value Changes On Nonrecurring Basis) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Principal amount of other real estate owned property sold	$ 1
Gains (losses) from fair value changes	(4)	$ (5)
Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gains (losses) from fair value changes	(4)	(4)
Private Equity Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gains (losses) from fair value changes	0	0
Other Real Estate Owned [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Gains (losses) from fair value changes	$ 0	$ (1)

Fair Value (Schedule Of Carryin

Fair Value (Schedule Of Carrying Values And Estimated Fair Values Of Financial Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Held-to-maturity, fair value	$ 762
Long-term Debt	1,228	$ 724
Fair Value, Inputs, Level 2 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt Securities, Held-to-maturity	764	774
Time deposits	4,928	4,336
Long-term Debt	1,228	724
Fair Value, Inputs, Level 3 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases (including loans held for sale), net of allowance	47,178	46,312
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Held-to-maturity, fair value	762	767
Time deposits	4,921	4,319
Long-term Debt	1,240	727
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Loans and leases (including loans held for sale), net of allowance	$ 46,197	$ 45,251

Offsetting Assets and Liabili_3

Offsetting Assets and Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell [Member] | Assets [Member]
Offsetting Assets [Line Items]
Net amount	$ 438	$ 1,461
Gross amounts recognized	739	1,461
Gross amounts offset in the balance sheet	(301)	0
Net amounts presented in the balance sheet	438	1,461
Gross amounts not offset in the balance sheet	0	0
Cash Collateral Received/Pledged	0	0
Derivative Financial Instruments, Assets [Member] | Assets [Member]
Offsetting Assets [Line Items]
Net amount	56	7
Gross amounts recognized	82	45
Gross amounts offset in the balance sheet	0	0
Net amounts presented in the balance sheet	82	45
Gross amounts not offset in the balance sheet	(21)	(35)
Cash Collateral Received/Pledged	(5)	(3)
Assets, Total [Member] | Assets [Member]
Offsetting Assets [Line Items]
Net amount	494	1,468
Gross amounts recognized	821	1,506
Gross amounts offset in the balance sheet	(301)	0
Net amounts presented in the balance sheet	520	1,506
Gross amounts not offset in the balance sheet	(21)	(35)
Cash Collateral Received/Pledged	(5)	(3)
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member] | Other Liabilities [Member]
Offsetting Assets [Line Items]
Net amount	4,944	5,653
Gross amounts recognized	5,245	5,653
Gross amounts offset in the balance sheet	(301)	0
Net amounts presented in the balance sheet	4,944	5,653
Gross amounts not offset in the balance sheet	0	0
Cash Collateral Received/Pledged	0	0
Derivative Financial Instruments, Liabilities [Member] | Other Liabilities [Member]
Offsetting Assets [Line Items]
Net amount	4	3
Gross amounts recognized	25	39
Gross amounts offset in the balance sheet	0	0
Net amounts presented in the balance sheet	25	39
Gross amounts not offset in the balance sheet	(21)	(35)
Cash Collateral Received/Pledged	0	(1)
Liabilities, Total [Member] | Other Liabilities [Member]
Offsetting Assets [Line Items]
Net amount	4,948	5,656
Gross amounts recognized	5,270	5,692
Gross amounts offset in the balance sheet	(301)	0
Net amounts presented in the balance sheet	4,969	5,692
Gross amounts not offset in the balance sheet	(21)	(35)
Cash Collateral Received/Pledged	$ 0	$ (1)

Investment Securities (Narrativ

Investment Securities (Narrative) (Details) $ in Millions	Mar. 31, 2019USD ($)Securities	Dec. 31, 2018USD ($)Securities
Investment [Line Items]
Other Real Estate, Foreclosed Assets, Residential Real Estate | $	$ 1	$ 2
Number of HTM investment securities in an unrealized loss position | Securities	464	606
Number of AFS investment securities in an unrealized loss position | Securities	1,891	2,588
Carrying value of pledged securities | $	$ 3,100

Investment Securities (Summary

Investment Securities (Summary Of Investment Securities) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Investment [Line Items]
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Amortized Cost	$ 252
Held-to-maturity, fair value	762
Debt Securities, Available-for-sale, Amortized Cost	15,045	$ 15,040
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I		23
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I		326
Debt Securities, Available-for-sale	14,904	14,737
Available-for-sale Securities, Gross Unrealized Gain	55
Available-for-sale, Amortized cost	15,045
Available-for-sale, Gross unrealized losses, Recognized in OCI	196
Available-for-sale securities, Estimated fair value	14,904	14,737
amortized cost of investment securities	15,809	15,814
Gross Unrealized Gains of Investment Securities Recognized in OCI	59	27
Gross Unrealized Losses of Investment Securities Recognized in OCI	202	337
Estimated Fair Value of Investment Securities	15,666	15,504
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value	252
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost	2,147
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value	2,125
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Rolling after One Through Five Years, Amortized Cost	329
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value	328
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost	5,984
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value	5,928
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Rolling after Five Through Ten Years, Amortized Cost	132
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value	132
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost	4,441
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value	4,406
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Amortized Cost	51
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value	50
Debt Securities, Available-for-sale, Allocated and Single Maturity Date, Maturity, after 10 Years, Amortized Cost	2,473
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value	2,445
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Amortized Cost	764
Available-for-sale, Other debt securities [Member]
Investment [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	25	25
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	0	0
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	3	4
Debt Securities, Available-for-sale	22	21
Small Business Administration Loan Backed Securities [Member]
Investment [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	1,919	2,042
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	1	1
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	43	47
Debt Securities, Available-for-sale	1,877	1,996
Agency Guaranteed Mortgage Backed Securities [Member]
Investment [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	10,384	10,236
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	36	18
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	136	240
Debt Securities, Available-for-sale	10,284	10,014
Agency Securities [Member]
Investment [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	1,407	1,394
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	2	0
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	11	19
Debt Securities, Available-for-sale	1,398	1,375
US Treasury Securities [Member]
Investment [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	40	40
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	0	0
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	0	0
Debt Securities, Available-for-sale	40	40
US States and Political Subdivisions Debt Securities [Member]
Investment [Line Items]
Held-to-maturity, fair value	762	767
Held-to-maturity, Amortized cost	764	774
Debt Securities, Available-for-sale, Amortized Cost	1,270	1,303
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	16	4
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	3	16
Debt Securities, Available-for-sale	1,283	1,291
Held-to-maturity Securities, Unrecognized Holding Gain (Deprecated 2018-01-31)	4	4
Held-to-maturity Securities, Unrecognized Holding Loss (Deprecated 2018-01-31)	$ 6	$ 11

Investment Securities (Contract

Investment Securities (Contractual Maturities Debt Securities) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Rolling within One Year, Amortized Cost	$ 252
Held-to-maturity, Due in one year or less, Estimated fair value	252
Held-to-maturity, Due after one year through five years, Amortized cost	329
Held-to-maturity, Due after one year through five years, Estimated fair value	328
Held-to-maturity, Due after five years through ten years, Amortized cost	132
Held-to-maturity, Due after five years through ten years, Estimated fair value	132
Debt Securities, Held-to-maturity, Maturity, Allocated and Single Maturity Date, Rolling after 10 Years, Amortized Cost	51
Held-to-maturity, Due after ten years, Estimated fair value	50
Held-to-maturity, Amortized cost	764
Held-to-maturity, fair value	762
Available-for-sale, Due in one year or less, Amortized cost	2,147
Available-for-sale, Due in one year or less, Estimated fair value	2,125
Available-for-sale, Due after one year through five years, Amortized cost	5,984
Available-for-sale, Due after one year through five years, Estimated fair value	5,928
Available-for-sale, Due after five years through ten years, Amortized cost	4,441
Available-for-sale, Due after five years through ten years, Estimated fair value	4,406
Available-for-sale, Due after ten years, Amortized cost	2,473
Available-for-sale, Due after ten years, Estimated fair value	2,445
Available-for-sale, Amortized cost	15,045	$ 15,040
Available-for-sale, Estimated fair value	$ 14,904	$ 14,737

Investment Securities (Summar_2

Investment Securities (Summary Of Amount Of Gross Unrealized Losses For Debt Securities And Estimated Fair Value) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Available-for-sale, Unrealized losses, Other [Member]
Investment [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ 0	$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	3	4
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	12	11
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	3	4
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	12	11
US States and Political Subdivisions Debt Securities [Member]
Investment [Line Items]
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	1
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	24	86
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	6	10
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	415	438
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	6	11
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	439	524
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	40	266
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	3	14
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	458	641
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	3	16
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	498	907
Small Business Administration Loan Backed Securities [Member]
Investment [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	13	19
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	876	1,180
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	30	28
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	898	711
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	43	47
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,774	1,891
Agency Guaranteed Mortgage Backed Securities [Member]
Investment [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2	16
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	270	1,081
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	134	224
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	6,799	6,661
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	136	240
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	7,069	7,742
Agency Securities [Member]
Investment [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	46	245
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	11	17
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	994	913
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	11	19
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	$ 1,040	$ 1,158

Investment Securities (Gains An

Investment Securities (Gains And Losses, Including OTTI, Recognized In Statement Of Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Investments [Abstract]
Other noninterest-bearing investments, Nonmarketable equity securities, Gross gains	$ 4	$ 1
Other noninterest-bearing investments, Nonmarketable equity securities, Gross losses	3	1
Gain (Loss) on Investments	$ 1	$ 0

Investment Securities Taxable a

Investment Securities Taxable and Nontaxable Interest Income by Investment Type (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Noninterest Income	$ 96	$ 86
Taxable [Member]
Noninterest Income	85	75
Nontaxable [Member]
Noninterest Income	11	11
Held-to-maturity Securities [Member]
Noninterest Income	6	6
Held-to-maturity Securities [Member] | Taxable [Member]
Noninterest Income	2	2
Held-to-maturity Securities [Member] | Nontaxable [Member]
Noninterest Income	4	4
Available-for-sale Securities [Member]
Noninterest Income	89	79
Available-for-sale Securities [Member] | Taxable [Member]
Noninterest Income	83	73
Available-for-sale Securities [Member] | Nontaxable [Member]
Noninterest Income	6	6
Other Trading [Member]
Noninterest Income	1	1
Other Trading [Member] | Taxable [Member]
Noninterest Income	0	0
Other Trading [Member] | Nontaxable [Member]
Noninterest Income	$ 1	$ 1

Investment Securities Noncredit

Investment Securities Noncredit impairment recognized in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Noncredit related impairment losses [Line Items]
Investment Income, Interest	$ 96	$ 86
Available-for-sale Securities [Member]
Noncredit related impairment losses [Line Items]
Investment Income, Interest	89	79
Held-to-maturity Securities [Member]
Noncredit related impairment losses [Line Items]
Investment Income, Interest	6	6
Taxable [Member]
Noncredit related impairment losses [Line Items]
Investment Income, Interest	85	75
Taxable [Member] | Available-for-sale Securities [Member]
Noncredit related impairment losses [Line Items]
Investment Income, Interest	83	73
Taxable [Member] | Held-to-maturity Securities [Member]
Noncredit related impairment losses [Line Items]
Investment Income, Interest	2	2
Nontaxable [Member]
Noncredit related impairment losses [Line Items]
Investment Income, Interest	11	11
Nontaxable [Member] | Available-for-sale Securities [Member]
Noncredit related impairment losses [Line Items]
Investment Income, Interest	6	6
Nontaxable [Member] | Held-to-maturity Securities [Member]
Noncredit related impairment losses [Line Items]
Investment Income, Interest	$ 4	$ 4

Loans And Allowance For Credi_3

Loans And Allowance For Credit Losses (Narrative) (Details) $ in Millions		3 Months Ended
		Mar. 31, 2019USD ($)d		Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Loans And Allowance For Credit Losses [Line Items]
Loans Credit Quality Outstanding, Commercial And Industrial		$ 14,758			$ 14,513
Impaired Financing Receivable, Average Recorded Investment		250		$ 379
Impaired Financing Receivable, Interest Income, Accrual Method		1		8
Impaired Financing Receivable, Recorded Investment		238			261
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment		9			9
Loans Modified As Troubled Debt Restructurings Loans		73		111
Unfunded Lending Commitments on Troubled Debt Restructuring		11
Loans and Leases Receivable, Gross		47,606			46,714
Financing Receivable, Recorded Investment, Current		47,360			46,539
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		5		2
Unearned income and fees, net of related costs		51			50
Land Development Loans		231			237
Loans at carrying value pledged as collateral for current and potential borrowings		23,000			23,000
Payments for Origination and Purchases of Loans Held-for-sale		93		165
Principal Balance of Loans Sold, Serviced Loans		2,200
Loans and Leases Receivable, Gain (Loss) on Sales, Net		2		3
Principle amount of loans held for sale sold		$ 118		106
Minimum number of days past due for nonaccrual status | d		90
Recorded investment in TDR loans modified with interest rates below market		$ 80			88
Provision for Loan and Lease Losses		2		(40)
Provision for Unfunded Lending Commitments (decrease)		2		(7)
Other Real Estate, Foreclosed Assets, and Repossessed Assets		1			2
Other Real Estate, In Process of Forecloseing Assets		9			10
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		167			89
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		79			86
Financing Receivable, Recorded Investment, Past Due		246			175
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		8			10
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	138			145
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment		488			486
Loans and Leases Receivable, Allowance		497		473	495	$ 518
Financing Receivable, Individually Evaluated for Impairment		268			291
Financing Receivable, Collectively Evaluated for Impairment		47,338			46,423
Loan Credit Quality Outstanding, Leasing		312			327
Commercial Lending Loans - Owner Occupied		7,754			7,661
Loans Credit Quality Outstanding, Municipal		1,774			1,661
Land Development Loans, Loans Receivable Commercial Construction and Land Development		2,343			2,186
Commercial Real Estate Term Loans		9,187			8,939
Loans Credit Quality Outstanding, Commercial Real Estate		11,530			11,125
Loans Credit Quality Outstanding, Home Equity Credit Line		2,884			2,937
Loans Credit Quality Outstanding, 1-4 Family Residential		7,294			7,176
Loans Credit Quality Outstanding, Construction and Other		636			643
Loans Credit Quality Outstanding, Bankcard		489			491
Loans Credit Quality Outstanding, Other		175			180
Impaired Financing Receivable, Related Allowance		8			8
Impaired Financing Receivable, Unpaid Principal Balance		275			310
Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment		1		1
Impaired Financing Receivable, Interest Income, Accrual Method		0		0
Impaired Financing Receivable, Recorded Investment		1			1
Financing Receivable, Recorded Investment, Nonaccrual Status		1			1
Impaired Financing Receivable, Related Allowance		0			0
Impaired Financing Receivable, Unpaid Principal Balance		1			1
Construction And Other Consumer Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment		2		2
Impaired Financing Receivable, Interest Income, Accrual Method		0		0
Impaired Financing Receivable, Recorded Investment		2			1
Financing Receivable, Recorded Investment, Nonaccrual Status		2			0
Impaired Financing Receivable, Related Allowance		0			0
Impaired Financing Receivable, Unpaid Principal Balance		2			1
One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment		55		55
Impaired Financing Receivable, Interest Income, Accrual Method		0		0
Impaired Financing Receivable, Recorded Investment		53			57
Financing Receivable, Recorded Investment, Nonaccrual Status		45			42
Impaired Financing Receivable, Related Allowance		2			2
Impaired Financing Receivable, Unpaid Principal Balance		63			69
Commercial And Industrial [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		79
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3		1
Financing Receivable, Recorded Investment, Nonaccrual Status		72			82
Impaired Financing Receivable, Related Allowance		5			4
Impaired Financing Receivable, Unpaid Principal Balance		99			112
Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment		14		20
Impaired Financing Receivable, Interest Income, Accrual Method		0		0
Impaired Financing Receivable, Recorded Investment		15			14
Financing Receivable, Recorded Investment, Nonaccrual Status		11			13
Impaired Financing Receivable, Related Allowance		0			0
Impaired Financing Receivable, Unpaid Principal Balance		15			15
Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment		71		77
Impaired Financing Receivable, Interest Income, Accrual Method		0		0
Impaired Financing Receivable, Recorded Investment		70			72
Financing Receivable, Recorded Investment, Nonaccrual Status		58			56
Impaired Financing Receivable, Related Allowance		2			2
Impaired Financing Receivable, Unpaid Principal Balance		80			85
Commercial [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans Credit Quality Outstanding, Commercial And Industrial		14,758			14,513
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment		6			6
Loans and Leases Receivable, Gross		$ 24,598			24,162
Subsequent payment default period, number of days | d		90
Provision for Loan and Lease Losses		$ (1)		(40)
Provision for Unfunded Lending Commitments (decrease)		2		(8)
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment		322			325
Loans and Leases Receivable, Allowance		328		329	331	371
Financing Receivable, Individually Evaluated for Impairment					164
Financing Receivable, Collectively Evaluated for Impairment					23,998
Loan Credit Quality Outstanding, Leasing		312			327
Commercial Lending Loans - Owner Occupied		7,754			7,661
Loans Credit Quality Outstanding, Municipal		1,774			1,661
Loans and Leases Receivable, before Fees, Gross		24,598			24,162
Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment		0		0
Impaired Financing Receivable, Interest Income, Accrual Method		0		0
Impaired Financing Receivable, Recorded Investment		0			0
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment		2			2
Loans and Leases Receivable, Gross		$ 11,478			11,427
Subsequent payment default period, number of days | d		60
Provision for Loan and Lease Losses		$ 2		1
Provision for Unfunded Lending Commitments (decrease)		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status		0			0
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment		54			52
Loans and Leases Receivable, Allowance		56		40	54	44
Financing Receivable, Individually Evaluated for Impairment					72
Financing Receivable, Collectively Evaluated for Impairment					11,355
Loans and Leases Receivable, before Fees, Gross		11,478			11,427
Loans Credit Quality Outstanding, Home Equity Credit Line		2,884			2,937
Loans Credit Quality Outstanding, 1-4 Family Residential		7,294			7,176
Loans Credit Quality Outstanding, Construction and Other		636			643
Loans Credit Quality Outstanding, Bankcard		489			491
Loans Credit Quality Outstanding, Other		175			180
Impaired Financing Receivable, Related Allowance		0			0
Impaired Financing Receivable, Unpaid Principal Balance		0			0
Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment		35		62
Impaired Financing Receivable, Interest Income, Accrual Method		0		0
Impaired Financing Receivable, Recorded Investment		35			40
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment					1
Loans and Leases Receivable, Gross		11,530			11,125
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2		0
Financing Receivable, Recorded Investment, Nonaccrual Status		33			38
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment					109
Loans and Leases Receivable, Allowance		113			110
Financing Receivable, Individually Evaluated for Impairment					55
Financing Receivable, Collectively Evaluated for Impairment					11,070
Impaired Financing Receivable, Related Allowance		0			0
Impaired Financing Receivable, Unpaid Principal Balance		39			45
Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment		0		5
Impaired Financing Receivable, Interest Income, Accrual Method		0		0
Impaired Financing Receivable, Recorded Investment					0
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment		1
Provision for Loan and Lease Losses		1		(1)
Provision for Unfunded Lending Commitments (decrease)		0		1
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment		112
Loans and Leases Receivable, Allowance		113		104	110	$ 103
Land Development Loans, Loans Receivable Commercial Construction and Land Development					2,186
Commercial Real Estate Term Loans		9,187			8,939
Loans Credit Quality Outstanding, Commercial Real Estate		11,530			11,125
Construction and Land Development [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		1			0
Land Development Loans, Loans Receivable Commercial Construction and Land Development		2,343
Commercial Real Estate Construction [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		0
Impaired Financing Receivable, Related Allowance		0			0
Impaired Financing Receivable, Unpaid Principal Balance		0			1
Bankcard And Other Revolving Plans [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		0			1
Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment		60		91
Impaired Financing Receivable, Interest Income, Accrual Method		0		8
Impaired Financing Receivable, Recorded Investment		53			60
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		1
Financing Receivable, Recorded Investment, Nonaccrual Status		69			67
Impaired Financing Receivable, Related Allowance		1			2
Impaired Financing Receivable, Unpaid Principal Balance		56			67
Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment		35		57
Impaired Financing Receivable, Interest Income, Accrual Method		0		0
Impaired Financing Receivable, Recorded Investment		35			40
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2		0
Financing Receivable, Recorded Investment, Nonaccrual Status		32			38
Impaired Financing Receivable, Related Allowance		0			0
Impaired Financing Receivable, Unpaid Principal Balance		39			44
Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		11,478			11,427
Financing Receivable, Recorded Investment, Current		11,430			11,378
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		22			23
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		26			26
Financing Receivable, Recorded Investment, Past Due		48			49
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1			2
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24			23
Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		175			180
Financing Receivable, Recorded Investment, Current					179
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due					1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due					0
Financing Receivable, Recorded Investment, Past Due		1			1
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing					0
Consumer Portfolio Segment [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		174
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0			0
Finance Leases Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		312			327
Financing Receivable, Recorded Investment, Current					325
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due					1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due					1
Financing Receivable, Recorded Investment, Past Due		1			2
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing					0
Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		7,754			7,661
Financing Receivable, Recorded Investment, Current					7,621
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due					23
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due					17
Financing Receivable, Recorded Investment, Past Due		52			40
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing					3
Owner Occupied [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		7,702
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		33
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		19
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	45			48
Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		1,774			1,661
Financing Receivable, Recorded Investment, Current					1,661
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due					0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due					0
Financing Receivable, Recorded Investment, Past Due		0			0
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing					0
Municipal [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		1,774
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	1			1
Commercial Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		24,598			24,162
Financing Receivable, Recorded Investment, Current		24,433			24,052
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		119			61
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		46			49
Financing Receivable, Recorded Investment, Past Due		165			110
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		5			7
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	90			96
Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		2,343			2,186
Financing Receivable, Recorded Investment, Current					2,185
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due					1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due					0
Financing Receivable, Recorded Investment, Past Due		10			1
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing					0
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		2,333
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		9
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		1
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0			0
Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		9,187			8,939
Financing Receivable, Recorded Investment, Current					8,924
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due					4
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due					11
Financing Receivable, Recorded Investment, Past Due		23			15
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing					1
Term [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		9,164
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		17
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		6
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24			26
Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		11,530			11,125
Financing Receivable, Recorded Investment, Current		11,497			11,109
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		26			5
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		7			11
Financing Receivable, Recorded Investment, Past Due		33			16
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		2			1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24			26
Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		2,884			2,937
Financing Receivable, Recorded Investment, Current					2,927
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due					4
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due					6
Financing Receivable, Recorded Investment, Past Due		9			10
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing					0
Home Equity Line of Credit [Member] | Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		2,875
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		5
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		4
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	5			4
One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		7,294			7,176
Financing Receivable, Recorded Investment, Current					7,143
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due					15
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due					18
Financing Receivable, Recorded Investment, Past Due		34			33
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing					0
One Through Four Family Residential [Member] | One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		7,260
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		13
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		21
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	17			19
Construction And Other Consumer Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		636			643
Financing Receivable, Recorded Investment, Current					642
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due					1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due					0
Financing Receivable, Recorded Investment, Past Due		0			1
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing					0
Construction And Other Consumer Real Estate [Member] | Construction And Other Consumer Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		636
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	2			0
Revolving Credit Facility [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		489			491
Financing Receivable, Recorded Investment, Current					487
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due					2
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due					2
Financing Receivable, Recorded Investment, Past Due		4			4
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing					2
Revolving Credit Facility [Member] | Bankcard And Other Revolving Plans [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		485
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		3
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		1
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0			0
Accruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		98			112
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		0
Accruing [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Accruing [Member] | One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		35			39
Accruing [Member] | Commercial And Industrial [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		26			28
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		0
Accruing [Member] | Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		12			12
Accruing [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		48			52
Accruing [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		9			11
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0
Accruing [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Accruing [Member] | Commercial Real Estate Construction [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Accruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		15			21
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		0
Accruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		9			11
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		0
Nonaccruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		174			202
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		5		2
Nonaccruing [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Nonaccruing [Member] | One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		9			9
Nonaccruing [Member] | Commercial And Industrial [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		32			45
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3		1
Nonaccruing [Member] | Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Nonaccruing [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		76			90
Nonaccruing [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		10			10
Nonaccruing [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		20			20
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2
Nonaccruing [Member] | Construction and Land Development [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment				0
Nonaccruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		13			14
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		1
Nonaccruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		20			20
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2		$ 0
Outstanding Loan Balances [Member] | Commercial [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment		148
Financing Receivable, Collectively Evaluated for Impairment		24,450
Outstanding Loan Balances [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment		70
Financing Receivable, Collectively Evaluated for Impairment		11,408
Outstanding Loan Balances [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment		50
Financing Receivable, Collectively Evaluated for Impairment		11,480
Pass [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		46,360			45,589
Pass [Member] | Commercial [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans Credit Quality Outstanding, Commercial And Industrial		14,047			13,891
Loan Credit Quality Outstanding, Leasing		299			313
Commercial Lending Loans - Owner Occupied		7,448			7,369
Loans Credit Quality Outstanding, Municipal		1,745			1,632
Loans and Leases Receivable, before Fees, Gross		23,539			23,205
Pass [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross		11,407			11,357
Loans Credit Quality Outstanding, Home Equity Credit Line		2,868			2,920
Loans Credit Quality Outstanding, 1-4 Family Residential		7,245			7,129
Loans Credit Quality Outstanding, Construction and Other		633			641
Loans Credit Quality Outstanding, Bankcard		487			488
Loans Credit Quality Outstanding, Other		174			179
Pass [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Land Development Loans, Loans Receivable Commercial Construction and Land Development					2,174
Commercial Real Estate Term Loans		9,080			8,853
Loans Credit Quality Outstanding, Commercial Real Estate		11,414			11,027
Pass [Member] | Construction and Land Development [Member]
Loans And Allowance For Credit Losses [Line Items]
Land Development Loans, Loans Receivable Commercial Construction and Land Development		2,334
Special Mention [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		517			427
Special Mention [Member] | Commercial [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans Credit Quality Outstanding, Commercial And Industrial		389			322
Loan Credit Quality Outstanding, Leasing		10			10
Commercial Lending Loans - Owner Occupied		82			72
Loans Credit Quality Outstanding, Municipal		2			2
Loans and Leases Receivable, before Fees, Gross		483			406
Special Mention [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross		0			0
Loans Credit Quality Outstanding, Home Equity Credit Line		0			0
Loans Credit Quality Outstanding, 1-4 Family Residential		0			0
Loans Credit Quality Outstanding, Construction and Other		0			0
Loans Credit Quality Outstanding, Bankcard		0			0
Loans Credit Quality Outstanding, Other		0			0
Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Land Development Loans, Loans Receivable Commercial Construction and Land Development					11
Commercial Real Estate Term Loans		34			10
Loans Credit Quality Outstanding, Commercial Real Estate		34			21
Special Mention [Member] | Construction and Land Development [Member]
Loans And Allowance For Credit Losses [Line Items]
Land Development Loans, Loans Receivable Commercial Construction and Land Development		0
Substandard [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		729			698
Substandard [Member] | Commercial [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans Credit Quality Outstanding, Commercial And Industrial		322			300
Loan Credit Quality Outstanding, Leasing		3			4
Commercial Lending Loans - Owner Occupied		224			220
Loans Credit Quality Outstanding, Municipal		27			27
Loans and Leases Receivable, before Fees, Gross		576			551
Substandard [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross		71			70
Loans Credit Quality Outstanding, Home Equity Credit Line		16			17
Loans Credit Quality Outstanding, 1-4 Family Residential		49			47
Loans Credit Quality Outstanding, Construction and Other		3			2
Loans Credit Quality Outstanding, Bankcard		2			3
Loans Credit Quality Outstanding, Other		1			1
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Land Development Loans, Loans Receivable Commercial Construction and Land Development					1
Commercial Real Estate Term Loans		73			76
Loans Credit Quality Outstanding, Commercial Real Estate		82			77
Substandard [Member] | Construction and Land Development [Member]
Loans And Allowance For Credit Losses [Line Items]
Land Development Loans, Loans Receivable Commercial Construction and Land Development		9
Doubtful [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		0			0
Doubtful [Member] | Commercial [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans Credit Quality Outstanding, Commercial And Industrial		0			0
Loan Credit Quality Outstanding, Leasing		0			0
Commercial Lending Loans - Owner Occupied		0			0
Loans Credit Quality Outstanding, Municipal		0			0
Loans and Leases Receivable, before Fees, Gross		0			0
Doubtful [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross		0			0
Loans Credit Quality Outstanding, Home Equity Credit Line		0			0
Loans Credit Quality Outstanding, 1-4 Family Residential		0			0
Loans Credit Quality Outstanding, Construction and Other		0			0
Loans Credit Quality Outstanding, Bankcard		0			0
Loans Credit Quality Outstanding, Other		0			0
Doubtful [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Land Development Loans, Loans Receivable Commercial Construction and Land Development					0
Commercial Real Estate Term Loans		0			0
Loans Credit Quality Outstanding, Commercial Real Estate		0			0
Doubtful [Member] | Construction and Land Development [Member]
Loans And Allowance For Credit Losses [Line Items]
Land Development Loans, Loans Receivable Commercial Construction and Land Development		0
SEC Schedule, 12-09, Allowance, Loan and Lease Loss [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		497			495
SEC Schedule, 12-09, Allowance, Loan and Lease Loss [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross		56
SEC Schedule, 12-09, Allowance, Loan and Lease Loss [Member] | Commercial [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross		328			331
SEC Schedule, 12-09, Allowance, Loan and Lease Loss [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross					54
SEC Schedule, 12-09, Allowance, Loan and Lease Loss [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans Credit Quality Outstanding, Commercial Real Estate		113			110
Impaired Financing Receivable Recorded Investment With No Allowance [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		153			166
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		1			1
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Construction And Other Consumer Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		0			1
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		30			32
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Commercial And Industrial [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		35			52
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		12			12
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		42			45
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		0			0
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		33			37
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Commercial Real Estate Construction [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		0			0
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		42			31
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		33			37
Impaired Financing Receivable Recorded Investment With an Allowance [Member] [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		0
Impaired Financing Receivable Recorded Investment With an Allowance [Member] [Member] | Construction And Other Consumer Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		2
Impaired Financing Receivable Recorded Investment With an Allowance [Member] [Member] | One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		23
Impaired Financing Receivable Recorded Investment With an Allowance [Member] [Member] | Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		3
Impaired Financing Receivable Recorded Investment With an Allowance [Member] [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		0
Impaired Financing Receivable Recorded Investment With an Allowance [Member] [Member] | Commercial Real Estate Construction [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		0
Impaired Financing Receivable Recorded Investment With an Allowance [Member] [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		11
Impaired Financing Receivable Recorded Investment With an Allowance [Member] [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		2
Impaired Financing Receivable Related Allowance [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		85			95
Impaired Financing Receivable Related Allowance [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment					0
Impaired Financing Receivable Related Allowance [Member] | Construction And Other Consumer Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment					0
Impaired Financing Receivable Related Allowance [Member] | One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment					25
Impaired Financing Receivable Related Allowance [Member] | Commercial And Industrial [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		44			36
Impaired Financing Receivable Related Allowance [Member] | Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment					2
Impaired Financing Receivable Related Allowance [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		28			27
Impaired Financing Receivable Related Allowance [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment					0
Impaired Financing Receivable Related Allowance [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment		2			3
Impaired Financing Receivable Related Allowance [Member] | Commercial Real Estate Construction [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment					0
Impaired Financing Receivable Related Allowance [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment					29
Impaired Financing Receivable Related Allowance [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment					3
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	18			18
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	1			1
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	0			0
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					2
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	25			45
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	7			27
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	1			1
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	3			14
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]				2
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]				14
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Accruing [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0	[2]		0
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Accruing [Member] | One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1	[2]		1
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Accruing [Member] | Commercial And Industrial [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		14	[2]		15
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Accruing [Member] | Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0	[2]		0
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Accruing [Member] | Commercial Real Estate Construction [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	0
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Accruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	3
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member] | Accruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	0
Multiple Modification Types [Member] | Accruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[3]	45			59
Multiple Modification Types [Member] | Accruing [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[3]	27			32
Multiple Modification Types [Member] | Accruing [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[3]	5			6
Multiple Modification Types [Member] | Accruing [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Multiple Modification Types [Member] | Accruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					14
Multiple Modification Types [Member] | Accruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					6
Multiple Modification Types [Member] | Nonaccruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[3]	95			100
Multiple Modification Types [Member] | Nonaccruing [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					1
Multiple Modification Types [Member] | Nonaccruing [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[3]	50			41
Multiple Modification Types [Member] | Nonaccruing [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[3]	7			7
Multiple Modification Types [Member] | Nonaccruing [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[3]	12			1
Multiple Modification Types [Member] | Nonaccruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[3]				5
Multiple Modification Types [Member] | Nonaccruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[3]				1
Multiple Modification Types [Member] | Accruing [Member] | Accruing [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Multiple Modification Types [Member] | Accruing [Member] | Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0	[3]		1
Multiple Modification Types [Member] | Accruing [Member] | Accruing [Member] | One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		25	[3]		28
Multiple Modification Types [Member] | Accruing [Member] | Accruing [Member] | Commercial And Industrial [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		6	[3]		7
Multiple Modification Types [Member] | Accruing [Member] | Accruing [Member] | Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		2	[3]		3
Multiple Modification Types [Member] | Accruing [Member] | Accruing [Member] | Commercial Real Estate Construction [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[3]	0
Multiple Modification Types [Member] | Accruing [Member] | Accruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[3]	7
Multiple Modification Types [Member] | Accruing [Member] | Accruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment	[3]	5
Interest Rate Below Market [Member] | Accruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		8			8
Interest Rate Below Market [Member] | Accruing [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Interest Rate Below Market [Member] | Accruing [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			2
Interest Rate Below Market [Member] | Accruing [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Interest Rate Below Market [Member] | Accruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					3
Interest Rate Below Market [Member] | Accruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					2
Interest Rate Below Market [Member] | Nonaccruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		18			18
Interest Rate Below Market [Member] | Nonaccruing [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Interest Rate Below Market [Member] | Nonaccruing [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		10			10
Interest Rate Below Market [Member] | Nonaccruing [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Interest Rate Below Market [Member] | Nonaccruing [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		3			3
Interest Rate Below Market [Member] | Nonaccruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					6
Interest Rate Below Market [Member] | Nonaccruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					3
Interest Rate Below Market [Member] | Accruing [Member] | Accruing [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Interest Rate Below Market [Member] | Accruing [Member] | Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Interest Rate Below Market [Member] | Accruing [Member] | Accruing [Member] | One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Interest Rate Below Market [Member] | Accruing [Member] | Accruing [Member] | Commercial And Industrial [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		2			2
Interest Rate Below Market [Member] | Accruing [Member] | Accruing [Member] | Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Interest Rate Below Market [Member] | Accruing [Member] | Accruing [Member] | Commercial Real Estate Construction [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Interest Rate Below Market [Member] | Accruing [Member] | Accruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		4
Interest Rate Below Market [Member] | Accruing [Member] | Accruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1
Maturity Or Team Extension [Member] | Accruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		10			11
Maturity Or Team Extension [Member] | Accruing [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		3			3
Maturity Or Team Extension [Member] | Accruing [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		2			2
Maturity Or Team Extension [Member] | Accruing [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Maturity Or Team Extension [Member] | Accruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					2
Maturity Or Team Extension [Member] | Accruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					2
Maturity Or Team Extension [Member] | Nonaccruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		14			17
Maturity Or Team Extension [Member] | Nonaccruing [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Maturity Or Team Extension [Member] | Nonaccruing [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		4			6
Maturity Or Team Extension [Member] | Nonaccruing [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Maturity Or Team Extension [Member] | Nonaccruing [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Maturity Or Team Extension [Member] | Nonaccruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Maturity Or Team Extension [Member] | Nonaccruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Maturity Or Team Extension [Member] | Accruing [Member] | Accruing [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Maturity Or Team Extension [Member] | Accruing [Member] | Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			0
Maturity Or Team Extension [Member] | Accruing [Member] | Accruing [Member] | One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			2
Maturity Or Team Extension [Member] | Accruing [Member] | Accruing [Member] | Commercial And Industrial [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		4			4
Maturity Or Team Extension [Member] | Accruing [Member] | Accruing [Member] | Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Maturity Or Team Extension [Member] | Accruing [Member] | Accruing [Member] | Commercial Real Estate Construction [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Maturity Or Team Extension [Member] | Accruing [Member] | Accruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1
Maturity Or Team Extension [Member] | Accruing [Member] | Accruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		2
Principal Forgiveness [Member] | Accruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		15			14
Principal Forgiveness [Member] | Accruing [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		15			14
Principal Forgiveness [Member] | Accruing [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Principal Forgiveness [Member] | Accruing [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Principal Forgiveness [Member] | Accruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Principal Forgiveness [Member] | Accruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Principal Forgiveness [Member] | Nonaccruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		17			16
Principal Forgiveness [Member] | Nonaccruing [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Principal Forgiveness [Member] | Nonaccruing [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		2			2
Principal Forgiveness [Member] | Nonaccruing [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		2			2
Principal Forgiveness [Member] | Nonaccruing [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Principal Forgiveness [Member] | Nonaccruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Principal Forgiveness [Member] | Nonaccruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Principal Forgiveness [Member] | Accruing [Member] | Accruing [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Principal Forgiveness [Member] | Accruing [Member] | Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Principal Forgiveness [Member] | Accruing [Member] | Accruing [Member] | One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		6			6
Principal Forgiveness [Member] | Accruing [Member] | Accruing [Member] | Commercial And Industrial [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Principal Forgiveness [Member] | Accruing [Member] | Accruing [Member] | Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		9			8
Principal Forgiveness [Member] | Accruing [Member] | Accruing [Member] | Commercial Real Estate Construction [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Principal Forgiveness [Member] | Accruing [Member] | Accruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Principal Forgiveness [Member] | Accruing [Member] | Accruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Payment Deferral [Member] | Accruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		2			2
Payment Deferral [Member] | Accruing [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Payment Deferral [Member] | Accruing [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Payment Deferral [Member] | Accruing [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Payment Deferral [Member] | Accruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Payment Deferral [Member] | Accruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					1
Payment Deferral [Member] | Nonaccruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		5			6
Payment Deferral [Member] | Nonaccruing [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Payment Deferral [Member] | Nonaccruing [Member] | Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		3			4
Payment Deferral [Member] | Nonaccruing [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Payment Deferral [Member] | Nonaccruing [Member] | Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		2			2
Payment Deferral [Member] | Nonaccruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					1
Payment Deferral [Member] | Nonaccruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment					2
Payment Deferral [Member] | Accruing [Member] | Accruing [Member] | Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Payment Deferral [Member] | Accruing [Member] | Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Payment Deferral [Member] | Accruing [Member] | Accruing [Member] | One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Payment Deferral [Member] | Accruing [Member] | Accruing [Member] | Commercial And Industrial [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Payment Deferral [Member] | Accruing [Member] | Accruing [Member] | Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			$ 0
Payment Deferral [Member] | Accruing [Member] | Accruing [Member] | Commercial Real Estate Construction [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Payment Deferral [Member] | Accruing [Member] | Accruing [Member] | Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Payment Deferral [Member] | Accruing [Member] | Accruing [Member] | Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		$ 1
[1]	1 Represents nonaccrual loans that are not past due more than 30 days; however, full payment of principal and interest is still not expected.
[2]	1 Includes TDRs that resulted from other modification types including, but not limited to, a legal judgment awarded on different terms, a bankruptcy plan confirmed on different terms, a settlement that includes the delivery of collateral in exchange for debt reduction, etc.
[3]	2 Includes TDRs that resulted from a combination of any of the previous modification types.

Loans And Allowance For Credi_4

Loans And Allowance For Credit Losses (Summary Of Major Portfolio Segment And Specific Loan Class) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at end of period	$ 497	$ 473
Loans held for sale	69		$ 93
Loans Credit Quality Outstanding, Commercial And Industrial	14,758		14,513
Loan Credit Quality Outstanding, Leasing	312		327
Owner occupied	7,754		7,661
Loans Credit Quality Outstanding, Municipal	1,774		1,661
Land Development Loans, Loans Receivable Commercial Construction and Land Development	2,343		2,186
Term	9,187		8,939
Loans Credit Quality Outstanding, Commercial Real Estate	11,530		11,125
Provision for loan losses	(2)	40
Allowance for Loan and Lease Losses, Write-offs	12	26
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	12	21
Net loan and lease charge-offs	0	5
Reserve for unfunded lending commitments	59	51	57	$ 58
Provision for Unfunded Lending Commitments (decrease)	2	(7)
Allowance for loan and lease losses and reserve for unfunded lending commitments	556	$ 524
Loans Credit Quality Outstanding, Home Equity Credit Line	2,884		2,937
Loans Credit Quality Outstanding, 1-4 Family Residential	7,294		7,176
Loans Credit Quality Outstanding, Construction and Other	636		643
Loans Credit Quality Outstanding, Bankcard	489		491
Loans Credit Quality Outstanding, Other	175		180
Loans and Leases Receivable, Gross	47,606		46,714
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross	24,598		24,162
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross	$ 11,478		$ 11,427

Loans And Allowance For Credi_5

Loans And Allowance For Credit Losses (Summary Of Changes In The Allowance For Credit Losses) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	$ (2)	$ 40
Allowance for Loan and Lease Losses, Write-offs	12	26
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	495	518
Allowance for Loan and Lease Losses, Adjustments, Other	0	5
Balance at end of period	59	51
Allowance for loan losses	495	518	$ 497	$ 495	$ 473	$ 518
Reserve for unfunded lending commitments	59	51	59	57	51	58
Allowance for loan and lease losses and reserve for unfunded lending commitments			556		524
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	12	21
Provision for Unfunded Lending Commitments (decrease)	2	(7)
Balance at end of period	497	473
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	1	40
Allowance for Loan and Lease Losses, Write-offs	8	20
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	331	371
Allowance for Loan and Lease Losses, Adjustments, Other	2	2
Balance at end of period	42	40
Allowance for loan losses	331	371	328	331	329	371
Reserve for unfunded lending commitments	42	40	42	40	40	48
Allowance for loan and lease losses and reserve for unfunded lending commitments			370		369
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	6	18
Provision for Unfunded Lending Commitments (decrease)	2	(8)
Balance at end of period	328	329
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	(1)	1
Allowance for Loan and Lease Losses, Write-offs	1	0
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	110	103
Allowance for Loan and Lease Losses, Adjustments, Other	(2)	(2)
Balance at end of period	17	11
Allowance for loan losses	110	103	113	110	104	103
Reserve for unfunded lending commitments	17	11	17	17	11	10
Allowance for loan and lease losses and reserve for unfunded lending commitments			130		115
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	3	2
Provision for Unfunded Lending Commitments (decrease)	0	1
Balance at end of period	113	104
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	(2)	(1)
Allowance for Loan and Lease Losses, Write-offs	3	6
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	54	44
Allowance for Loan and Lease Losses, Adjustments, Other	0	5
Balance at end of period	0	0
Allowance for loan losses	54	44	56	54	40	44
Reserve for unfunded lending commitments	0	0	0	$ 0	0	$ 0
Allowance for loan and lease losses and reserve for unfunded lending commitments			$ 56		$ 40
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	3	1
Provision for Unfunded Lending Commitments (decrease)	0	0
Balance at end of period	$ 56	$ 40

Loans And Allowance For Credi_6

Loans And Allowance For Credit Losses (Summary Of ALLL And Outstanding Loan Balances According To The Company's Impairment Method) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$ 250	$ 379
Impaired Financing Receivable, Interest Income, Accrual Method	1	8
Allowance for loan losses: Individually evaluated for impairment	(9)		$ (9)
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	488		486
Financing Receivable, Individually Evaluated for Impairment	268		291
Financing Receivable, Collectively Evaluated for Impairment	47,338		46,423
Loans and Leases Receivable, Gross	47,606		46,714
Loans and Leases Receivable, Allowance	497	473	495	$ 518
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	60	91
Impaired Financing Receivable, Interest Income, Accrual Method	0	8
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Individually evaluated for impairment	(6)		(6)
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	322		325
Financing Receivable, Individually Evaluated for Impairment			164
Financing Receivable, Collectively Evaluated for Impairment			23,998
Loans and Leases Receivable, Gross	24,598		24,162
Loans and Leases Receivable, Allowance	328	329	331	371
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	0	5
Impaired Financing Receivable, Interest Income, Accrual Method	0	0
Allowance for loan losses: Individually evaluated for impairment	(1)
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	112
Loans and Leases Receivable, Allowance	113	104	110	103
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	0	0
Impaired Financing Receivable, Interest Income, Accrual Method	0	0
Allowance for loan losses: Individually evaluated for impairment	(2)		(2)
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	54		52
Financing Receivable, Individually Evaluated for Impairment			72
Financing Receivable, Collectively Evaluated for Impairment			11,355
Loans and Leases Receivable, Gross	11,478		11,427
Loans and Leases Receivable, Allowance	56	40	54	$ 44
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	144	240
Impaired Financing Receivable, Interest Income, Accrual Method	1	8
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	35	57
Impaired Financing Receivable, Interest Income, Accrual Method	0	0
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	35	62
Impaired Financing Receivable, Interest Income, Accrual Method	0	0
Allowance for loan losses: Individually evaluated for impairment			(1)
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment			109
Financing Receivable, Individually Evaluated for Impairment			55
Financing Receivable, Collectively Evaluated for Impairment			11,070
Loans and Leases Receivable, Gross	11,530		11,125
Loans and Leases Receivable, Allowance	113		$ 110
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	14	20
Impaired Financing Receivable, Interest Income, Accrual Method	0	0
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	55	55
Impaired Financing Receivable, Interest Income, Accrual Method	0	0
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	2	2
Impaired Financing Receivable, Interest Income, Accrual Method	0	0
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	71	77
Impaired Financing Receivable, Interest Income, Accrual Method	0	0
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	1	1
Impaired Financing Receivable, Interest Income, Accrual Method	0	$ 0
Outstanding Loan Balances [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	148
Financing Receivable, Collectively Evaluated for Impairment	24,450
Outstanding Loan Balances [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	50
Financing Receivable, Collectively Evaluated for Impairment	11,480
Outstanding Loan Balances [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Individually Evaluated for Impairment	70
Financing Receivable, Collectively Evaluated for Impairment	$ 11,408

Loans And Allowance For Credi_7

Loans And Allowance For Credit Losses (Summary Of Nonaccrual Loans) (Details) - USD ($) $ in Millions		Mar. 31, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	[1]	$ 138	$ 145
loans held for sale [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		0	6
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		0	0
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		1	2
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		69	67
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		1	1
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		143	152
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		32	38
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		33	38
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		11	13
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		45	42
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		2	0
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		58	56
Financing Receivables, Total [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		$ 234	$ 246
[1]	1 Represents nonaccrual loans that are not past due more than 30 days; however, full payment of principal and interest is still not expected.

Loans And Allowance For Credi_8

Loans And Allowance For Credit Losses (Summary Of Past Due Loans (Accruing And Nonaccruing)) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 5	$ 2
Financing Receivable, Recorded Investment, Current		47,360		$ 46,539
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		167		89
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		79		86
Financing Receivable, Recorded Investment, Past Due		246		175
Loans and Leases Receivable, Gross		47,606		46,714
Accruing loans 90+ days past due		8		10
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	138		145
Bankcard And Other Revolving Plans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		0		1
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3	1
Financing Receivable, Recorded Investment, Nonaccrual Status		72		82
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		24,598		24,162
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3	2
Financing Receivable, Recorded Investment, Nonaccrual Status		143		152
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		11,478		11,427
Financing Receivable, Recorded Investment, Nonaccrual Status		0		0
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		58		56
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		1		2
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	1
Financing Receivable, Recorded Investment, Nonaccrual Status		69		67
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		1		1
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	0
Financing Receivable, Recorded Investment, Nonaccrual Status		32		38
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	0
Loans and Leases Receivable, Gross		11,530		11,125
Financing Receivable, Recorded Investment, Nonaccrual Status		33		38
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		11		13
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		45		42
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		2		0
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		11,430		11,378
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		22		23
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		26		26
Financing Receivable, Recorded Investment, Past Due		48		49
Loans and Leases Receivable, Gross		11,478		11,427
Accruing loans 90+ days past due		1		2
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24		23
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				179
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				0
Financing Receivable, Recorded Investment, Past Due		1		1
Loans and Leases Receivable, Gross		175		180
Accruing loans 90+ days past due				0
Consumer Portfolio Segment [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		174
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0
Accruing loans 90+ days past due		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0
Revolving Credit Facility [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				487
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				2
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				2
Financing Receivable, Recorded Investment, Past Due		4		4
Loans and Leases Receivable, Gross		489		491
Accruing loans 90+ days past due				2
Revolving Credit Facility [Member] | Bankcard And Other Revolving Plans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		485
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		3
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		1
Accruing loans 90+ days past due		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				642
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				0
Financing Receivable, Recorded Investment, Past Due		0		1
Loans and Leases Receivable, Gross		636		643
Accruing loans 90+ days past due				0
Construction And Other Consumer Real Estate [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		636
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0
Accruing loans 90+ days past due		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	2		0
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				7,143
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				15
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				18
Financing Receivable, Recorded Investment, Past Due		34		33
Loans and Leases Receivable, Gross		7,294		7,176
Accruing loans 90+ days past due				0
One Through Four Family Residential [Member] | One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		7,260
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		13
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		21
Accruing loans 90+ days past due		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	17		19
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				2,927
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				4
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				6
Financing Receivable, Recorded Investment, Past Due		9		10
Loans and Leases Receivable, Gross		2,884		2,937
Accruing loans 90+ days past due				0
Home Equity Line of Credit [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		2,875
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		5
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		4
Accruing loans 90+ days past due		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	5		4
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		11,497		11,109
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		26		5
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		7		11
Financing Receivable, Recorded Investment, Past Due		33		16
Loans and Leases Receivable, Gross		11,530		11,125
Accruing loans 90+ days past due		2		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24		26
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				8,924
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				4
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				11
Financing Receivable, Recorded Investment, Past Due		23		15
Loans and Leases Receivable, Gross		9,187		8,939
Accruing loans 90+ days past due				1
Term [Member] | Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		9,164
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		17
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		6
Accruing loans 90+ days past due		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24		26
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				2,185
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				0
Financing Receivable, Recorded Investment, Past Due		10		1
Loans and Leases Receivable, Gross		2,343		2,186
Accruing loans 90+ days past due				0
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		2,333
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		9
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		1
Accruing loans 90+ days past due		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		24,433		24,052
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		119		61
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		46		49
Financing Receivable, Recorded Investment, Past Due		165		110
Loans and Leases Receivable, Gross		24,598		24,162
Accruing loans 90+ days past due		5		7
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	90		96
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				1,661
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				0
Financing Receivable, Recorded Investment, Past Due		0		0
Loans and Leases Receivable, Gross		1,774		1,661
Accruing loans 90+ days past due				0
Municipal [Member] | Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		1,774
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0
Accruing loans 90+ days past due		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	1		1
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				7,621
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				23
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				17
Financing Receivable, Recorded Investment, Past Due		52		40
Loans and Leases Receivable, Gross		7,754		7,661
Accruing loans 90+ days past due				3
Owner Occupied [Member] | Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		7,702
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		33
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		19
Accruing loans 90+ days past due		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	45		48
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				325
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				1
Financing Receivable, Recorded Investment, Past Due		1		2
Loans and Leases Receivable, Gross		312		327
Accruing loans 90+ days past due				0
Finance Leases Portfolio Segment [Member] | Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		311
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		1
Accruing loans 90+ days past due		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	1		1
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				14,445
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				37
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				31
Financing Receivable, Recorded Investment, Past Due		112		68
Loans and Leases Receivable, Gross		14,758		14,513
Accruing loans 90+ days past due				4
Commercial And Industrial [Member] | Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		14,646
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		86
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		26
Accruing loans 90+ days past due		4
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	43		46
loans held for sale [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		69		89
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		0		0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0		4
Financing Receivable, Recorded Investment, Past Due		0		4
Loans and Leases Receivable, Gross		69		93
Accruing loans 90+ days past due		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		$ 2
Accruing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Accruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Accruing [Member] | Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Accruing [Member] | Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Accruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0
Nonaccruing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		5	2
Nonaccruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3	1
Nonaccruing [Member] | Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3	2
Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	1
Nonaccruing [Member] | Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	$ 0
Nonaccruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 2
[1]	1 Represents nonaccrual loans that are not past due more than 30 days; however, full payment of principal and interest is still not expected.

Loans And Allowance For Credi_9

Loans And Allowance For Credit Losses (Summary Of Outstanding Loan Balances (Accruing And Nonaccruing) Categorized By Credit Quality Indicators) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans Credit Quality Outstanding, Commercial And Industrial		$ 14,758		$ 14,513
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		5	$ 2
Financing Receivable, Recorded Investment, Current		47,360		46,539
Loans held for sale		69		93
Loan Credit Quality Outstanding, Leasing		312		327
Owner occupied		7,754		7,661
Municipal		1,774		1,661
Land Development Loans, Loans Receivable Commercial Construction and Land Development		2,343		2,186
Term		9,187		8,939
Loans Credit Quality Outstanding, Commercial Real Estate		11,530		11,125
Loans Credit Quality Outstanding, Home Equity Credit Line		2,884		2,937
Loans Credit Quality Outstanding, 1-4 Family Residential		7,294		7,176
Loans Credit Quality Outstanding, Construction and Other		636		643
Loans Credit Quality Outstanding, Bankcard		489		491
Other		175		180
Loans and Leases Receivable, Gross		47,606		46,714
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		167		89
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		79		86
Financing Receivable, Recorded Investment, Past Due		246		175
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		8		10
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	138		145
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross		11,478		11,427
Loans Credit Quality Outstanding, Home Equity Credit Line		2,884		2,937
Loans Credit Quality Outstanding, 1-4 Family Residential		7,294		7,176
Loans Credit Quality Outstanding, Construction and Other		636		643
Loans Credit Quality Outstanding, Bankcard		489		491
Other		175		180
Loans and Leases Receivable, Gross		11,478		11,427
Financing Receivable, Recorded Investment, Nonaccrual Status		0		0
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Land Development Loans, Loans Receivable Commercial Construction and Land Development				2,186
Term		9,187		8,939
Loans Credit Quality Outstanding, Commercial Real Estate		11,530		11,125
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans Credit Quality Outstanding, Commercial And Industrial		14,758		14,513
Loan Credit Quality Outstanding, Leasing		312		327
Owner occupied		7,754		7,661
Municipal		1,774		1,661
Loans and Leases Receivable, before Fees, Gross		24,598		24,162
Loans and Leases Receivable, Gross		24,598		24,162
Pass [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		46,360		45,589
Pass [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross		11,407		11,357
Loans Credit Quality Outstanding, Home Equity Credit Line		2,868		2,920
Loans Credit Quality Outstanding, 1-4 Family Residential		7,245		7,129
Loans Credit Quality Outstanding, Construction and Other		633		641
Loans Credit Quality Outstanding, Bankcard		487		488
Other		174		179
Pass [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Land Development Loans, Loans Receivable Commercial Construction and Land Development				2,174
Term		9,080		8,853
Loans Credit Quality Outstanding, Commercial Real Estate		11,414		11,027
Pass [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans Credit Quality Outstanding, Commercial And Industrial		14,047		13,891
Loan Credit Quality Outstanding, Leasing		299		313
Owner occupied		7,448		7,369
Municipal		1,745		1,632
Loans and Leases Receivable, before Fees, Gross		23,539		23,205
Special Mention [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		517		427
Special Mention [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross		0		0
Loans Credit Quality Outstanding, Home Equity Credit Line		0		0
Loans Credit Quality Outstanding, 1-4 Family Residential		0		0
Loans Credit Quality Outstanding, Construction and Other		0		0
Loans Credit Quality Outstanding, Bankcard		0		0
Other		0		0
Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Land Development Loans, Loans Receivable Commercial Construction and Land Development				11
Term		34		10
Loans Credit Quality Outstanding, Commercial Real Estate		34		21
Special Mention [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans Credit Quality Outstanding, Commercial And Industrial		389		322
Loan Credit Quality Outstanding, Leasing		10		10
Owner occupied		82		72
Municipal		2		2
Loans and Leases Receivable, before Fees, Gross		483		406
SEC Schedule, 12-09, Allowance, Loan and Lease Loss [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		497		495
SEC Schedule, 12-09, Allowance, Loan and Lease Loss [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross				54
SEC Schedule, 12-09, Allowance, Loan and Lease Loss [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans Credit Quality Outstanding, Commercial Real Estate		113		110
SEC Schedule, 12-09, Allowance, Loan and Lease Loss [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross		328		331
Doubtful [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		0		0
Doubtful [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross		0		0
Loans Credit Quality Outstanding, Home Equity Credit Line		0		0
Loans Credit Quality Outstanding, 1-4 Family Residential		0		0
Loans Credit Quality Outstanding, Construction and Other		0		0
Loans Credit Quality Outstanding, Bankcard		0		0
Other		0		0
Doubtful [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Land Development Loans, Loans Receivable Commercial Construction and Land Development				0
Term		0		0
Loans Credit Quality Outstanding, Commercial Real Estate		0		0
Doubtful [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans Credit Quality Outstanding, Commercial And Industrial		0		0
Loan Credit Quality Outstanding, Leasing		0		0
Owner occupied		0		0
Municipal		0		0
Loans and Leases Receivable, before Fees, Gross		0		0
Substandard [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		729		698
Substandard [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, before Fees, Gross		71		70
Loans Credit Quality Outstanding, Home Equity Credit Line		16		17
Loans Credit Quality Outstanding, 1-4 Family Residential		49		47
Loans Credit Quality Outstanding, Construction and Other		3		2
Loans Credit Quality Outstanding, Bankcard		2		3
Other		1		1
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Land Development Loans, Loans Receivable Commercial Construction and Land Development				1
Term		73		76
Loans Credit Quality Outstanding, Commercial Real Estate		82		77
Substandard [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans Credit Quality Outstanding, Commercial And Industrial		322		300
Loan Credit Quality Outstanding, Leasing		3		4
Owner occupied		224		220
Municipal		27		27
Loans and Leases Receivable, before Fees, Gross		576		551
loans held for sale [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		69		89
Loans and Leases Receivable, Gross		69		93
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		0		0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0		4
Financing Receivable, Recorded Investment, Past Due		0		4
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		2
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				14,445
Loans and Leases Receivable, Gross		14,758		14,513
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				37
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				31
Financing Receivable, Recorded Investment, Past Due		112		68
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing				4
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		11,430		11,378
Loans and Leases Receivable, Gross		11,478		11,427
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		22		23
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		26		26
Financing Receivable, Recorded Investment, Past Due		48		49
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1		2
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24		23
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				179
Loans and Leases Receivable, Gross		175		180
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				0
Financing Receivable, Recorded Investment, Past Due		1		1
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing				0
Consumer Portfolio Segment [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		174
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				8,924
Loans and Leases Receivable, Gross		9,187		8,939
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				4
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				11
Financing Receivable, Recorded Investment, Past Due		23		15
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing				1
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				2,185
Loans and Leases Receivable, Gross		2,343		2,186
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				0
Financing Receivable, Recorded Investment, Past Due		10		1
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing				0
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		2,333
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		9
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		1
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				325
Loans and Leases Receivable, Gross		312		327
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				1
Financing Receivable, Recorded Investment, Past Due		1		2
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing				0
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				7,621
Loans and Leases Receivable, Gross		7,754		7,661
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				23
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				17
Financing Receivable, Recorded Investment, Past Due		52		40
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing				3
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				1,661
Loans and Leases Receivable, Gross		1,774		1,661
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				0
Financing Receivable, Recorded Investment, Past Due		0		0
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing				0
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		11,497		11,109
Loans and Leases Receivable, Gross		11,530		11,125
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		26		5
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		7		11
Financing Receivable, Recorded Investment, Past Due		33		16
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		2		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24		26
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				2,927
Loans and Leases Receivable, Gross		2,884		2,937
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				4
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				6
Financing Receivable, Recorded Investment, Past Due		9		10
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing				0
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		24,433		24,052
Loans and Leases Receivable, Gross		24,598		24,162
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		119		61
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		46		49
Financing Receivable, Recorded Investment, Past Due		165		110
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		5		7
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	90		96
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				7,143
Loans and Leases Receivable, Gross		7,294		7,176
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				15
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				18
Financing Receivable, Recorded Investment, Past Due		34		33
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing				0
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				642
Loans and Leases Receivable, Gross		636		643
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				0
Financing Receivable, Recorded Investment, Past Due		$ 0		1
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing				$ 0
[1]	1 Represents nonaccrual loans that are not past due more than 30 days; however, full payment of principal and interest is still not expected.

Loans And Allowance For Cred_10

Loans And Allowance For Credit Losses (Summary Of Information On Impaired Loans) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	$ 275		$ 310
Impaired Financing Receivable, Recorded Investment	238		261
Impaired Financing Receivable, Related Allowance	8		8
Average recorded investment	250	$ 379
Interest income recognized	1	8
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	99		112
Impaired Financing Receivable, Recorded Investment	79
Impaired Financing Receivable, Related Allowance	5		4
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	56		67
Impaired Financing Receivable, Recorded Investment	53		60
Impaired Financing Receivable, Related Allowance	1		2
Average recorded investment	60	91
Interest income recognized	0	8
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	1		1
Impaired Financing Receivable, Recorded Investment	1		1
Impaired Financing Receivable, Related Allowance	0		0
Average recorded investment	1	1
Interest income recognized	0	0
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	156		180
Impaired Financing Receivable, Recorded Investment	133		149
Impaired Financing Receivable, Related Allowance	6		6
Average recorded investment	144	240
Interest income recognized	1	8
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment			0
Average recorded investment	0	5
Interest income recognized	0	0
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	39		44
Impaired Financing Receivable, Recorded Investment	35		40
Impaired Financing Receivable, Related Allowance	0		0
Average recorded investment	35	57
Interest income recognized	0	0
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	39		45
Impaired Financing Receivable, Recorded Investment	35		40
Impaired Financing Receivable, Related Allowance	0		0
Average recorded investment	35	62
Interest income recognized	0	0
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	15		15
Impaired Financing Receivable, Recorded Investment	15		14
Impaired Financing Receivable, Related Allowance	0		0
Average recorded investment	14	20
Interest income recognized	0	0
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	0		0
Impaired Financing Receivable, Recorded Investment	0		0
Impaired Financing Receivable, Related Allowance	0		0
Average recorded investment	0	0
Interest income recognized	0	0
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	63		69
Impaired Financing Receivable, Recorded Investment	53		57
Impaired Financing Receivable, Related Allowance	2		2
Average recorded investment	55	55
Interest income recognized	0	0
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	2		1
Impaired Financing Receivable, Recorded Investment	2		1
Impaired Financing Receivable, Related Allowance	0		0
Average recorded investment	2	2
Interest income recognized	0	0
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	80		85
Impaired Financing Receivable, Recorded Investment	70		72
Impaired Financing Receivable, Related Allowance	2		2
Average recorded investment	71	77
Interest income recognized	0	0
Impaired Financing Receivable Related Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	85		95
Impaired Financing Receivable Related Allowance [Member] | Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	44		36
Impaired Financing Receivable Related Allowance [Member] | Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment			29
Impaired Financing Receivable Related Allowance [Member] | Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment			0
Impaired Financing Receivable Related Allowance [Member] | Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	55		65
Impaired Financing Receivable Related Allowance [Member] | Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment			3
Impaired Financing Receivable Related Allowance [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	2		3
Impaired Financing Receivable Related Allowance [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment			2
Impaired Financing Receivable Related Allowance [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment			0
Impaired Financing Receivable Related Allowance [Member] | One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment			25
Impaired Financing Receivable Related Allowance [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment			0
Impaired Financing Receivable Related Allowance [Member] | Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	28		27
Impaired Financing Receivable Recorded Investment With No Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	153		166
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	35		52
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	42		31
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	1		1
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	78		84
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	33		37
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	33		37
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	12		12
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	0		0
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	30		32
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	0		1
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment	42		45
Commercial and Industrial Sector [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Recorded Investment			$ 88
Average recorded investment	83
Interest income recognized	$ 1
Commercial and Industrial Sector [Member] | Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Average recorded investment		148
Interest income recognized		$ 0

Loans And Allowance For Cred_11

Loans And Allowance For Credit Losses (Summary Of Selected Information On TDRs That Includes Recorded Investment On An Accruing And Nonaccruing Basis By Loan Class And Modification Type) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019		Mar. 31, 2018	Dec. 31, 2018
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 5		$ 2
Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3		1
Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		1
Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3		2
Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2		0
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2		0
Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		0
Recorded investment resulting from the following modification types		98			$ 112
Accruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		0
Recorded investment resulting from the following modification types		26			28
Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		0
Recorded investment resulting from the following modification types		15			21
Accruing [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		0
Recorded investment resulting from the following modification types		41			49
Accruing [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		0
Recorded investment resulting from the following modification types		9			11
Accruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0
Recorded investment resulting from the following modification types		9			11
Accruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		35			39
Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			1
Accruing [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		48			52
Accruing [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		12			12
Accruing [Member] | Interest Rate Below Market [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		8			8
Accruing [Member] | Interest Rate Below Market [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					3
Accruing [Member] | Interest Rate Below Market [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		6			5
Accruing [Member] | Interest Rate Below Market [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					2
Accruing [Member] | Interest Rate Below Market [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			2
Accruing [Member] | Interest Rate Below Market [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			1
Accruing [Member] | Maturity Or Team Extension [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		10			11
Accruing [Member] | Maturity Or Team Extension [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					2
Accruing [Member] | Maturity Or Team Extension [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		5			6
Accruing [Member] | Maturity Or Team Extension [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					2
Accruing [Member] | Maturity Or Team Extension [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2			2
Accruing [Member] | Maturity Or Team Extension [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		3			3
Accruing [Member] | Principal Forgiveness [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		15			14
Accruing [Member] | Principal Forgiveness [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					0
Accruing [Member] | Principal Forgiveness [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Accruing [Member] | Principal Forgiveness [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					0
Accruing [Member] | Principal Forgiveness [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Accruing [Member] | Principal Forgiveness [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		15			14
Accruing [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2			2
Accruing [Member] | Payment Deferral [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					0
Accruing [Member] | Payment Deferral [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Accruing [Member] | Payment Deferral [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					1
Accruing [Member] | Payment Deferral [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			1
Accruing [Member] | Payment Deferral [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			1
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	18			18
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					2
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	17			17
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					0
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	0			0
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	1			1
Accruing [Member] | Multiple Modification Types [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	45			59
Accruing [Member] | Multiple Modification Types [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					14
Accruing [Member] | Multiple Modification Types [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	13			21
Accruing [Member] | Multiple Modification Types [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					6
Accruing [Member] | Multiple Modification Types [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	5			6
Accruing [Member] | Multiple Modification Types [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	27			32
Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		5		2
Recorded investment resulting from the following modification types		174			202
Nonaccruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3		1
Recorded investment resulting from the following modification types		32			45
Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		1
Recorded investment resulting from the following modification types		13			14
Nonaccruing [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			1
Nonaccruing [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3		2
Recorded investment resulting from the following modification types		46			60
Nonaccruing [Member] | Construction and Land Development [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment				0
Nonaccruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2		$ 0
Recorded investment resulting from the following modification types		20			20
Nonaccruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2
Recorded investment resulting from the following modification types		20			20
Nonaccruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		9			9
Nonaccruing [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		10			10
Nonaccruing [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		76			90
Nonaccruing [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			1
Nonaccruing [Member] | Interest Rate Below Market [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		18			18
Nonaccruing [Member] | Interest Rate Below Market [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					6
Nonaccruing [Member] | Interest Rate Below Market [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					0
Nonaccruing [Member] | Interest Rate Below Market [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		7			7
Nonaccruing [Member] | Interest Rate Below Market [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					3
Nonaccruing [Member] | Interest Rate Below Market [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		3			3
Nonaccruing [Member] | Interest Rate Below Market [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Nonaccruing [Member] | Interest Rate Below Market [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		10			10
Nonaccruing [Member] | Maturity Or Team Extension [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		14			17
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		4			6
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		4			6
Nonaccruing [Member] | Principal Forgiveness [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		17			16
Nonaccruing [Member] | Principal Forgiveness [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					0
Nonaccruing [Member] | Principal Forgiveness [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					0
Nonaccruing [Member] | Principal Forgiveness [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Nonaccruing [Member] | Principal Forgiveness [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					0
Nonaccruing [Member] | Principal Forgiveness [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Nonaccruing [Member] | Principal Forgiveness [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2			2
Nonaccruing [Member] | Principal Forgiveness [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2			2
Nonaccruing [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		5			6
Nonaccruing [Member] | Payment Deferral [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					1
Nonaccruing [Member] | Payment Deferral [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					0
Nonaccruing [Member] | Payment Deferral [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			2
Nonaccruing [Member] | Payment Deferral [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					2
Nonaccruing [Member] | Payment Deferral [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2			2
Nonaccruing [Member] | Payment Deferral [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Nonaccruing [Member] | Payment Deferral [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		3			4
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	25			45
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]				2
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					0
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	3			12
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]				14
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	3			14
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	1			1
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	7			27
Nonaccruing [Member] | Multiple Modification Types [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	95			100
Nonaccruing [Member] | Multiple Modification Types [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]				5
Nonaccruing [Member] | Multiple Modification Types [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types					1
Nonaccruing [Member] | Multiple Modification Types [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	31			33
Nonaccruing [Member] | Multiple Modification Types [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]				1
Nonaccruing [Member] | Multiple Modification Types [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	12			1
Nonaccruing [Member] | Multiple Modification Types [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	7			7
Nonaccruing [Member] | Multiple Modification Types [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	50			41
Accruing [Member] | Accruing [Member] | Interest Rate Below Market [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2			2
Accruing [Member] | Accruing [Member] | Interest Rate Below Market [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		4
Accruing [Member] | Accruing [Member] | Interest Rate Below Market [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Accruing [Member] | Interest Rate Below Market [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Accruing [Member] | Interest Rate Below Market [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1
Accruing [Member] | Accruing [Member] | Interest Rate Below Market [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			1
Accruing [Member] | Accruing [Member] | Interest Rate Below Market [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Accruing [Member] | Accruing [Member] | Interest Rate Below Market [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Accruing [Member] | Accruing [Member] | Maturity Or Team Extension [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		4			4
Accruing [Member] | Accruing [Member] | Maturity Or Team Extension [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1
Accruing [Member] | Accruing [Member] | Maturity Or Team Extension [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Accruing [Member] | Maturity Or Team Extension [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Accruing [Member] | Maturity Or Team Extension [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2
Accruing [Member] | Accruing [Member] | Maturity Or Team Extension [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			2
Accruing [Member] | Accruing [Member] | Maturity Or Team Extension [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			0
Accruing [Member] | Accruing [Member] | Maturity Or Team Extension [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			1
Accruing [Member] | Accruing [Member] | Principal Forgiveness [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Accruing [Member] | Accruing [Member] | Principal Forgiveness [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Accruing [Member] | Principal Forgiveness [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Accruing [Member] | Principal Forgiveness [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Accruing [Member] | Principal Forgiveness [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Accruing [Member] | Principal Forgiveness [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		6			6
Accruing [Member] | Accruing [Member] | Principal Forgiveness [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Accruing [Member] | Accruing [Member] | Principal Forgiveness [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		9			8
Accruing [Member] | Accruing [Member] | Payment Deferral [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Accruing [Member] | Accruing [Member] | Payment Deferral [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Accruing [Member] | Payment Deferral [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Accruing [Member] | Payment Deferral [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Accruing [Member] | Payment Deferral [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1
Accruing [Member] | Accruing [Member] | Payment Deferral [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			1
Accruing [Member] | Accruing [Member] | Payment Deferral [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Accruing [Member] | Accruing [Member] | Payment Deferral [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Accruing [Member] | Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		14	[1]		15
Accruing [Member] | Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	3
Accruing [Member] | Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	0
Accruing [Member] | Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	0
Accruing [Member] | Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1	[1]		1
Accruing [Member] | Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0	[1]		0
Accruing [Member] | Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0	[1]		0
Accruing [Member] | Accruing [Member] | Multiple Modification Types [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		6	[2]		7
Accruing [Member] | Accruing [Member] | Multiple Modification Types [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	7
Accruing [Member] | Accruing [Member] | Multiple Modification Types [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Accruing [Member] | Accruing [Member] | Multiple Modification Types [Member] | Commercial Real Estate Construction [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	0
Accruing [Member] | Accruing [Member] | Multiple Modification Types [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	5
Accruing [Member] | Accruing [Member] | Multiple Modification Types [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		25	[2]		28
Accruing [Member] | Accruing [Member] | Multiple Modification Types [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0	[2]		1
Accruing [Member] | Accruing [Member] | Multiple Modification Types [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2	[2]		3
Nonaccruing [Member] | Nonaccruing [Member] | Interest Rate Below Market [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			1
Nonaccruing [Member] | Nonaccruing [Member] | Interest Rate Below Market [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		6
Nonaccruing [Member] | Nonaccruing [Member] | Interest Rate Below Market [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Nonaccruing [Member] | Nonaccruing [Member] | Interest Rate Below Market [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		3
Nonaccruing [Member] | Nonaccruing [Member] | Interest Rate Below Market [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Nonaccruing [Member] | Nonaccruing [Member] | Interest Rate Below Market [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Nonaccruing [Member] | Nonaccruing [Member] | Maturity Or Team Extension [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		4			6
Nonaccruing [Member] | Nonaccruing [Member] | Maturity Or Team Extension [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Nonaccruing [Member] | Nonaccruing [Member] | Maturity Or Team Extension [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Nonaccruing [Member] | Nonaccruing [Member] | Maturity Or Team Extension [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Nonaccruing [Member] | Nonaccruing [Member] | Maturity Or Team Extension [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Nonaccruing [Member] | Nonaccruing [Member] | Maturity Or Team Extension [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Nonaccruing [Member] | Nonaccruing [Member] | Principal Forgiveness [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Nonaccruing [Member] | Nonaccruing [Member] | Principal Forgiveness [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Nonaccruing [Member] | Nonaccruing [Member] | Principal Forgiveness [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Nonaccruing [Member] | Nonaccruing [Member] | Principal Forgiveness [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Nonaccruing [Member] | Nonaccruing [Member] | Principal Forgiveness [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			1
Nonaccruing [Member] | Nonaccruing [Member] | Principal Forgiveness [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			1
Nonaccruing [Member] | Nonaccruing [Member] | Payment Deferral [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1			1
Nonaccruing [Member] | Nonaccruing [Member] | Payment Deferral [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Nonaccruing [Member] | Nonaccruing [Member] | Payment Deferral [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Nonaccruing [Member] | Nonaccruing [Member] | Payment Deferral [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2
Nonaccruing [Member] | Nonaccruing [Member] | Payment Deferral [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Nonaccruing [Member] | Nonaccruing [Member] | Payment Deferral [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0			0
Nonaccruing [Member] | Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	2			10
Nonaccruing [Member] | Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	1
Nonaccruing [Member] | Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0
Nonaccruing [Member] | Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	3
Nonaccruing [Member] | Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	1			1
Nonaccruing [Member] | Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	0			0
Nonaccruing [Member] | Nonaccruing [Member] | Multiple Modification Types [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	24			27
Nonaccruing [Member] | Nonaccruing [Member] | Multiple Modification Types [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	6
Nonaccruing [Member] | Nonaccruing [Member] | Multiple Modification Types [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1
Nonaccruing [Member] | Nonaccruing [Member] | Multiple Modification Types [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	12
Nonaccruing [Member] | Nonaccruing [Member] | Multiple Modification Types [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	7			7
Nonaccruing [Member] | Nonaccruing [Member] | Multiple Modification Types [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	$ 0			$ 0
[1]	1 Includes TDRs that resulted from other modification types including, but not limited to, a legal judgment awarded on different terms, a bankruptcy plan confirmed on different terms, a settlement that includes the delivery of collateral in exchange for debt reduction, etc.
[2]	2 Includes TDRs that resulted from a combination of any of the previous modification types.

Loans And Allowance For Cred_12

Loans And Allowance For Credit Losses (Summary Of Net Financial Impact On Interest Income Due To Interest Rate Modifications Below Market For Accruing TDR Loans) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 5	$ 2
Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	1
Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	3	2
Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	2	0
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	2	0
Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	5	2
Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	1
Nonaccruing [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	3	2
Nonaccruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	2	0
Nonaccruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	2
Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0
Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0
Accruing [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0
Accruing [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	$ 0
Accruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0

Loans And Allowance For Cred_13

Loans And Allowance For Credit Losses (Schedule Of Investment Of Accruing And Nonaccruing Loans Modified As Troubled Debt Restructurings) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019		Mar. 31, 2018	Dec. 31, 2018
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 5		$ 2
Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		0
Financing Receivable, Modifications, Recorded Investment		98			$ 112
Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		5		2
Financing Receivable, Modifications, Recorded Investment		174			202
Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3		1
Commercial And Industrial [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		0
Financing Receivable, Modifications, Recorded Investment		26			28
Commercial And Industrial [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3		1
Financing Receivable, Modifications, Recorded Investment		32			45
Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		1
Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		0
Financing Receivable, Modifications, Recorded Investment		15			21
Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		1
Financing Receivable, Modifications, Recorded Investment		13			14
Municipal [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Municipal [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3		2
Commercial Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		0
Financing Receivable, Modifications, Recorded Investment		41			49
Commercial Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3		2
Financing Receivable, Modifications, Recorded Investment		46			60
Commercial Real Estate Portfolio Segment [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2		0
Term [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0		0
Financing Receivable, Modifications, Recorded Investment		9			11
Term [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2		0
Financing Receivable, Modifications, Recorded Investment		20			20
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2		$ 0
Commercial Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0
Financing Receivable, Modifications, Recorded Investment		9			11
Commercial Real Estate [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2
Financing Receivable, Modifications, Recorded Investment		20			20
Home Equity Line of Credit [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		12			12
Home Equity Line of Credit [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
One Through Four Family Residential [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		35			39
One Through Four Family Residential [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		9			9
Construction And Other Consumer Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Consumer Portfolio Segment [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		10			10
Consumer Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		48			52
Consumer Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		76			90
Interest Rate Below Market [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		8			8
Interest Rate Below Market [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		18			18
Interest Rate Below Market [Member] | Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					3
Interest Rate Below Market [Member] | Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					6
Interest Rate Below Market [Member] | Municipal [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Interest Rate Below Market [Member] | Commercial Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		6			5
Interest Rate Below Market [Member] | Commercial Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		7			7
Interest Rate Below Market [Member] | Commercial Real Estate Portfolio Segment [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Interest Rate Below Market [Member] | Term [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					2
Interest Rate Below Market [Member] | Term [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					3
Interest Rate Below Market [Member] | Commercial Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			2
Interest Rate Below Market [Member] | Commercial Real Estate [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		3			3
Interest Rate Below Market [Member] | Consumer Portfolio Segment [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Interest Rate Below Market [Member] | Consumer Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Interest Rate Below Market [Member] | Consumer Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		10			10
Maturity Or Team Extension [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		10			11
Maturity Or Team Extension [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		14			17
Maturity Or Team Extension [Member] | Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					2
Maturity Or Team Extension [Member] | Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Maturity Or Team Extension [Member] | Municipal [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Maturity Or Team Extension [Member] | Commercial Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		5			6
Maturity Or Team Extension [Member] | Commercial Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		4			6
Maturity Or Team Extension [Member] | Commercial Real Estate Portfolio Segment [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Maturity Or Team Extension [Member] | Term [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					2
Maturity Or Team Extension [Member] | Term [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Maturity Or Team Extension [Member] | Commercial Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		2			2
Maturity Or Team Extension [Member] | Commercial Real Estate [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Maturity Or Team Extension [Member] | Consumer Portfolio Segment [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Maturity Or Team Extension [Member] | Consumer Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		3			3
Maturity Or Team Extension [Member] | Consumer Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		4			6
Principal Forgiveness [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		15			14
Principal Forgiveness [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		17			16
Principal Forgiveness [Member] | Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Principal Forgiveness [Member] | Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Principal Forgiveness [Member] | Municipal [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Principal Forgiveness [Member] | Commercial Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Principal Forgiveness [Member] | Commercial Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Principal Forgiveness [Member] | Commercial Real Estate Portfolio Segment [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Principal Forgiveness [Member] | Term [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Principal Forgiveness [Member] | Term [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Principal Forgiveness [Member] | Commercial Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Principal Forgiveness [Member] | Commercial Real Estate [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Principal Forgiveness [Member] | Consumer Portfolio Segment [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		2			2
Principal Forgiveness [Member] | Consumer Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		15			14
Principal Forgiveness [Member] | Consumer Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		2			2
Payment Deferral [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		2			2
Payment Deferral [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		5			6
Payment Deferral [Member] | Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Payment Deferral [Member] | Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					1
Payment Deferral [Member] | Municipal [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Payment Deferral [Member] | Commercial Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Payment Deferral [Member] | Commercial Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			2
Payment Deferral [Member] | Commercial Real Estate Portfolio Segment [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Payment Deferral [Member] | Term [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					1
Payment Deferral [Member] | Term [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					2
Payment Deferral [Member] | Commercial Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Payment Deferral [Member] | Commercial Real Estate [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		2			2
Payment Deferral [Member] | Consumer Portfolio Segment [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Payment Deferral [Member] | Consumer Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Payment Deferral [Member] | Consumer Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		3			4
Other Recorded Investment Resulting From Following Modification [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	18			18
Other Recorded Investment Resulting From Following Modification [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	25			45
Other Recorded Investment Resulting From Following Modification [Member] | Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					2
Other Recorded Investment Resulting From Following Modification [Member] | Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]				2
Other Recorded Investment Resulting From Following Modification [Member] | Municipal [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Other Recorded Investment Resulting From Following Modification [Member] | Commercial Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	17			17
Other Recorded Investment Resulting From Following Modification [Member] | Commercial Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	3			12
Other Recorded Investment Resulting From Following Modification [Member] | Commercial Real Estate Portfolio Segment [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Other Recorded Investment Resulting From Following Modification [Member] | Term [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Other Recorded Investment Resulting From Following Modification [Member] | Term [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]				14
Other Recorded Investment Resulting From Following Modification [Member] | Commercial Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	0			0
Other Recorded Investment Resulting From Following Modification [Member] | Commercial Real Estate [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	3			14
Other Recorded Investment Resulting From Following Modification [Member] | Consumer Portfolio Segment [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	1			1
Other Recorded Investment Resulting From Following Modification [Member] | Consumer Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	1			1
Other Recorded Investment Resulting From Following Modification [Member] | Consumer Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	7			27
Multiple Modification Types [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	45			59
Multiple Modification Types [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	95			100
Multiple Modification Types [Member] | Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					14
Multiple Modification Types [Member] | Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]				5
Multiple Modification Types [Member] | Municipal [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					1
Multiple Modification Types [Member] | Commercial Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	13			21
Multiple Modification Types [Member] | Commercial Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	31			33
Multiple Modification Types [Member] | Commercial Real Estate Portfolio Segment [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					0
Multiple Modification Types [Member] | Term [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment					6
Multiple Modification Types [Member] | Term [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]				1
Multiple Modification Types [Member] | Commercial Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	5			6
Multiple Modification Types [Member] | Commercial Real Estate [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	12			1
Multiple Modification Types [Member] | Consumer Portfolio Segment [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	7			7
Multiple Modification Types [Member] | Consumer Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	27			32
Multiple Modification Types [Member] | Consumer Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	50			41
Nonaccruing [Member] | Interest Rate Below Market [Member] | Commercial And Industrial [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Nonaccruing [Member] | Interest Rate Below Market [Member] | Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		6
Nonaccruing [Member] | Interest Rate Below Market [Member] | Municipal [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Nonaccruing [Member] | Interest Rate Below Market [Member] | Term [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		3
Nonaccruing [Member] | Interest Rate Below Market [Member] | Home Equity Line of Credit [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Nonaccruing [Member] | Interest Rate Below Market [Member] | One Through Four Family Residential [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Commercial And Industrial [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		4			6
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Municipal [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Term [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Home Equity Line of Credit [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | One Through Four Family Residential [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Nonaccruing [Member] | Principal Forgiveness [Member] | Commercial And Industrial [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Nonaccruing [Member] | Principal Forgiveness [Member] | Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Municipal [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Term [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Home Equity Line of Credit [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Nonaccruing [Member] | Principal Forgiveness [Member] | One Through Four Family Residential [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Nonaccruing [Member] | Payment Deferral [Member] | Commercial And Industrial [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Nonaccruing [Member] | Payment Deferral [Member] | Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Nonaccruing [Member] | Payment Deferral [Member] | Municipal [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Nonaccruing [Member] | Payment Deferral [Member] | Term [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		2
Nonaccruing [Member] | Payment Deferral [Member] | Home Equity Line of Credit [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Nonaccruing [Member] | Payment Deferral [Member] | One Through Four Family Residential [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial And Industrial [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	2			10
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	1
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Municipal [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Term [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	3
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Home Equity Line of Credit [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	0			0
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | One Through Four Family Residential [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	1			1
Nonaccruing [Member] | Multiple Modification Types [Member] | Commercial And Industrial [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	24			27
Nonaccruing [Member] | Multiple Modification Types [Member] | Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	6
Nonaccruing [Member] | Multiple Modification Types [Member] | Municipal [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1
Nonaccruing [Member] | Multiple Modification Types [Member] | Term [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	12
Nonaccruing [Member] | Multiple Modification Types [Member] | Home Equity Line of Credit [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	0			0
Nonaccruing [Member] | Multiple Modification Types [Member] | One Through Four Family Residential [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	7			7
Accruing [Member] | Interest Rate Below Market [Member] | Commercial And Industrial [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		2			2
Accruing [Member] | Interest Rate Below Market [Member] | Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		4
Accruing [Member] | Interest Rate Below Market [Member] | Municipal [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Accruing [Member] | Interest Rate Below Market [Member] | Term [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1
Accruing [Member] | Interest Rate Below Market [Member] | Home Equity Line of Credit [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Accruing [Member] | Interest Rate Below Market [Member] | One Through Four Family Residential [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Accruing [Member] | Interest Rate Below Market [Member] | Construction And Other Consumer Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Accruing [Member] | Maturity Or Team Extension [Member] | Commercial And Industrial [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		4			4
Accruing [Member] | Maturity Or Team Extension [Member] | Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1
Accruing [Member] | Maturity Or Team Extension [Member] | Municipal [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Accruing [Member] | Maturity Or Team Extension [Member] | Term [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		2
Accruing [Member] | Maturity Or Team Extension [Member] | Home Equity Line of Credit [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Accruing [Member] | Maturity Or Team Extension [Member] | One Through Four Family Residential [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			2
Accruing [Member] | Maturity Or Team Extension [Member] | Construction And Other Consumer Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			0
Accruing [Member] | Principal Forgiveness [Member] | Commercial And Industrial [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Accruing [Member] | Principal Forgiveness [Member] | Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Accruing [Member] | Principal Forgiveness [Member] | Municipal [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Accruing [Member] | Principal Forgiveness [Member] | Term [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Accruing [Member] | Principal Forgiveness [Member] | Home Equity Line of Credit [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		9			8
Accruing [Member] | Principal Forgiveness [Member] | One Through Four Family Residential [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		6			6
Accruing [Member] | Principal Forgiveness [Member] | Construction And Other Consumer Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Accruing [Member] | Payment Deferral [Member] | Commercial And Industrial [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Accruing [Member] | Payment Deferral [Member] | Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Accruing [Member] | Payment Deferral [Member] | Municipal [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Accruing [Member] | Payment Deferral [Member] | Term [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1
Accruing [Member] | Payment Deferral [Member] | Home Equity Line of Credit [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Accruing [Member] | Payment Deferral [Member] | One Through Four Family Residential [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1			1
Accruing [Member] | Payment Deferral [Member] | Construction And Other Consumer Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0			0
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial And Industrial [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		14	[1]		15
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	3
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Municipal [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Term [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[1]	0
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Home Equity Line of Credit [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0	[1]		0
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | One Through Four Family Residential [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		1	[1]		1
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Construction And Other Consumer Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0	[1]		0
Accruing [Member] | Multiple Modification Types [Member] | Commercial And Industrial [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		6	[2]		7
Accruing [Member] | Multiple Modification Types [Member] | Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	7
Accruing [Member] | Multiple Modification Types [Member] | Municipal [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		0
Accruing [Member] | Multiple Modification Types [Member] | Term [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	[2]	5
Accruing [Member] | Multiple Modification Types [Member] | Home Equity Line of Credit [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		2	[2]		3
Accruing [Member] | Multiple Modification Types [Member] | One Through Four Family Residential [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		25	[2]		28
Accruing [Member] | Multiple Modification Types [Member] | Construction And Other Consumer Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment		$ 0	[2]		$ 1
[1]	1 Includes TDRs that resulted from other modification types including, but not limited to, a legal judgment awarded on different terms, a bankruptcy plan confirmed on different terms, a settlement that includes the delivery of collateral in exchange for debt reduction, etc.
[2]	2 Includes TDRs that resulted from a combination of any of the previous modification types.

Loans And Allowance For Cred_14

Loans And Allowance For Credit Losses (Schedule Of Outstanding Balances Of All Required Payments And The Related Carrying Amounts For PCI Loans) (Details) - USD ($) $ in Millions		Mar. 31, 2019	Dec. 31, 2018
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		$ 246	$ 175
Financing Receivable, Recorded Investment, Current		47,360	46,539
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		167	89
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		79	86
Loans and Leases Receivable, Gross		47,606	46,714
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		8	10
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	138	145
loans held for sale [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		0	4
Financing Receivable, Recorded Investment, Current		69	89
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		0	0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0	4
Loans and Leases Receivable, Gross		69	93
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0	2
Commercial And Industrial [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		112	68
Financing Receivable, Recorded Investment, Current			14,445
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due			37
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due			31
Loans and Leases Receivable, Gross		14,758	14,513
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			4
Finance Leases Portfolio Segment [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		1	2
Financing Receivable, Recorded Investment, Current			325
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due			1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due			1
Loans and Leases Receivable, Gross		312	327
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Owner Occupied [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		52	40
Financing Receivable, Recorded Investment, Current			7,621
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due			23
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due			17
Loans and Leases Receivable, Gross		7,754	7,661
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			3
Municipal [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		0	0
Financing Receivable, Recorded Investment, Current			1,661
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due			0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due			0
Loans and Leases Receivable, Gross		1,774	1,661
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Commercial Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		165	110
Financing Receivable, Recorded Investment, Current		24,433	24,052
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		119	61
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		46	49
Loans and Leases Receivable, Gross		24,598	24,162
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		5	7
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	90	96
Commercial Real Estate Portfolio Segment [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		10	1
Financing Receivable, Recorded Investment, Current			2,185
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due			1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due			0
Loans and Leases Receivable, Gross		2,343	2,186
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Term [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		23	15
Financing Receivable, Recorded Investment, Current			8,924
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due			4
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due			11
Loans and Leases Receivable, Gross		9,187	8,939
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			1
Commercial Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		33	16
Financing Receivable, Recorded Investment, Current		11,497	11,109
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		26	5
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		7	11
Loans and Leases Receivable, Gross		11,530	11,125
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		2	1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24	26
Home Equity Line of Credit [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		9	10
Financing Receivable, Recorded Investment, Current			2,927
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due			4
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due			6
Loans and Leases Receivable, Gross		2,884	2,937
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
One Through Four Family Residential [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		34	33
Financing Receivable, Recorded Investment, Current			7,143
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due			15
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due			18
Loans and Leases Receivable, Gross		7,294	7,176
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Construction And Other Consumer Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		0	1
Financing Receivable, Recorded Investment, Current			642
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due			1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due			0
Loans and Leases Receivable, Gross		636	643
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Revolving Credit Facility [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		4	4
Financing Receivable, Recorded Investment, Current			487
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due			2
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due			2
Loans and Leases Receivable, Gross		489	491
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			2
Consumer Portfolio Segment [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		1	1
Financing Receivable, Recorded Investment, Current			179
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due			1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due			0
Loans and Leases Receivable, Gross		175	180
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Consumer Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		48	49
Financing Receivable, Recorded Investment, Current		11,430	11,378
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		22	23
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		26	26
Loans and Leases Receivable, Gross		11,478	11,427
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1	2
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	$ 24	$ 23
[1]	1 Represents nonaccrual loans that are not past due more than 30 days; however, full payment of principal and interest is still not expected.

Derivative Instruments And He_4

Derivative Instruments And Hedging Activities (Narrative) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Derivative [Line Items]
Derivative Instruments, Gain Reclassified from Accumulated OCI into Income, Effective Portion		$ (7)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax		11	$ (5)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		2	0
Fair values of derivative assets reduced (increased) by net credit valuation adjustments		6	1
Total derivatives, Notional amount		$ 12,224		$ 7,481
Derivative, Floor Interest Rate		1.50%
Derivative, Average Remaining Maturity		2 years 8 months 4 days
Derivative, Average Fixed Interest Rate 2.08%		2.08%
Senior Notes		$ 1,141		637
Derivative, Cost of Hedge		7
Floors Purchased as Hedging Instruments		$ 9
Derivative, Fixed Interest Rate		3.35%
Derivative, Fixed Interest Rate 3.5%		3.50%
Derivative, Average Fixed Interest Rate		3.43%
Derivative, Notional Amount Commercial Loans		$ 1,300		700
Derivative Asset, Notional Amount		150
Cash collateral pledged for derivative liabilities		50
Additional collateral that would be required to be pledge if credit rating was downgraded by one notch		1
Derivative Instrument, Noninterest Income (Expense)		8	10
Derivatives Designated As Hedging Instrument Offset To Interest Expense		0	0
Derivative Credit Risk Valuation Adjustment, Derivative Liabilities		1	1
Derivatives Designated As Hedging Instruments [Member]
Derivative [Line Items]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax		11	(5)
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net		2	0
Total derivatives, Notional amount		5,338		1,187
Derivatives Designated As Hedging Instrument Offset To Interest Expense		0	0
Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivatives, Notional amount		6,886		6,294
Derivative Instrument, Noninterest Income (Expense)		8	10
Interest Rate Swap [Member] | Derivatives Designated As Hedging Instruments [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Total derivatives, Notional amount		1,000		500
Interest Rate Swap [Member] | Derivatives Designated As Hedging Instruments [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax		8
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	[1]	2
Total derivatives, Notional amount		1,338		687
Interest Rate Swap [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivatives, Notional amount		449		253
Derivative Instrument, Noninterest Income (Expense)		0	(2)
Interest Rate Swaps For Customers [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivatives, Notional amount		3,035		2,826
Derivative Instrument, Noninterest Income (Expense)		(41)	45
Foreign Exchange [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivatives, Notional amount		367		389
Derivative Instrument, Noninterest Income (Expense)		5	$ 5
Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		25		39
Other Liabilities [Member] | Derivatives Designated As Hedging Instruments [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		0		0
Other Liabilities [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		25		39
Other Liabilities [Member] | Derivative Financial Instruments, Liabilities [Member]
Derivative [Line Items]
Gross amounts recognized		25		39
Other Liabilities [Member] | Interest Rate Swap [Member] | Derivatives Designated As Hedging Instruments [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		0		0
Other Liabilities [Member] | Interest Rate Swap [Member] | Derivatives Designated As Hedging Instruments [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		0		0
Other Liabilities [Member] | Interest Rate Swap [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		1		1
Other Liabilities [Member] | Interest Rate Swaps For Customers [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		22		36
Other Liabilities [Member] | Foreign Exchange [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability		2		$ 2
Senior Notes [Member]
Derivative [Line Items]
Senior Notes		$ 500
[1]	Amounts recognized in OCI and reclassified from AOCI represent the effective portion of the derivative gain (loss). For the 12 months following March 31, 2019, we estimate that $(7) million will be reclassified from AOCI into interest income

Derivative Instruments And He_5

Derivative Instruments And Hedging Activities (Schedule Of Notional Amounts And Recorded Gross Fair Values And Related Gain (Loss) Of Derivative Instruments) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Derivative [Line Items]
Long-term Debt		$ 1,228,000		$ 724,000
Interest Rate Derivatives, at Fair Value, Net		$ 0	$ 0
Types of Items Hedged by Interest Rate Derivatives		6000000	0
Increase (Decrease) in Fair Value of Hedged Item in Interest Rate Fair Value Hedge		$ (6,000)	$ 0
Total derivatives, Notional amount		12,224,000		7,481,000
Amount of derivative gain (loss), recognized in OCI		11,000	(5,000)
Amount of derivative gain (loss), Reclassified from AOCI to interest income		2,000	0
Derivatives instruments, Noninterest income (expense)		8,000	10,000
Derivatives designated as hedging instruments, Offset to interest expense		0	0
Long-term Debt [Member]
Derivative [Line Items]
Hedged Liability, Fair Value Hedge		(1,010,000)		(505,000)
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)		(10,000)		(5,000)
Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		82,000		45,000
Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		25,000		39,000
Derivatives Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivatives, Notional amount		5,338,000		1,187,000
Amount of derivative gain (loss), recognized in OCI		11,000	(5,000)
Amount of derivative gain (loss), Reclassified from AOCI to interest income		2,000	0
Derivatives designated as hedging instruments, Offset to interest expense		0	0
Derivatives Designated As Hedging Instruments [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		9,000		0
Derivatives Designated As Hedging Instruments [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		0		0
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Floor [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Total derivatives, Notional amount		3,000,000		0
Amount of derivative gain (loss), recognized in OCI		3,000	(5,000)
Amount of derivative gain (loss), Reclassified from AOCI to interest income		0	0
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Floor [Member] | Other Assets [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		9,000		0
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Floor [Member] | Other Liabilities [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		0		0
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swap [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Total derivatives, Notional amount		1,338,000		687,000
Amount of derivative gain (loss), recognized in OCI		8,000
Amount of derivative gain (loss), Reclassified from AOCI to interest income	[1]	2,000
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swap [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Total derivatives, Notional amount		1,000,000		500,000
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swap [Member] | Other Assets [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		0		0
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swap [Member] | Other Assets [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		0		0
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swap [Member] | Other Liabilities [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		0		0
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swap [Member] | Other Liabilities [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		0		0
Derivatives Designated As Hedging Instruments [Member] | Terminated Swaps On Long Term Debt [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Derivatives designated as hedging instruments, Offset to interest expense		0	0
Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivatives, Notional amount		6,886,000		6,294,000
Derivatives instruments, Noninterest income (expense)		8,000	10,000
Derivatives Not Designated As Hedging Instruments [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		73,000		45,000
Derivatives Not Designated As Hedging Instruments [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		25,000		39,000
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange [Member]
Derivative [Line Items]
Total derivatives, Notional amount		367,000		389,000
Derivatives instruments, Noninterest income (expense)		5,000	5,000
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		3,000		4,000
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		2,000		2,000
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Total derivatives, Notional amount		449,000		253,000
Derivatives instruments, Noninterest income (expense)		0	(2,000)
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swap [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		1,000		1,000
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swap [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		1,000		1,000
Derivatives Not Designated As Hedging Instruments [Member] | Offsetting Interest Rate Derivatives [Member]
Derivative [Line Items]
Total derivatives, Notional amount		3,035,000		2,826,000
Derivatives instruments, Noninterest income (expense)		44,000	(38,000)
Derivatives Not Designated As Hedging Instruments [Member] | Offsetting Interest Rate Derivatives [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		0		0
Derivatives Not Designated As Hedging Instruments [Member] | Offsetting Interest Rate Derivatives [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		0		0
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member]
Derivative [Line Items]
Total derivatives, Notional amount		3,035,000		2,826,000
Derivatives instruments, Noninterest income (expense)		(41,000)	$ 45,000
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets		69,000		40,000
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities		$ 22,000		$ 36,000
[1]	Amounts recognized in OCI and reclassified from AOCI represent the effective portion of the derivative gain (loss). For the 12 months following March 31, 2019, we estimate that $(7) million will be reclassified from AOCI into interest income

Leases Leases (Narrivate) (Deta

Leases Leases (Narrivate) (Details $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)Branches	Mar. 31, 2018USD ($)
Leases (Narrivate) (Details) [Abstract]
Sales-type and Direct Financing Leases, Lease Receivable	$ 312	$ 371
Operating Lease, Lease Income	$ 2	3
Number of Branches | Branches	433
Number of Branches Owned | Branches	276
Number of Branches Leased | Branches	157
Operating Lease, Right-of-Use Asset	$ 244
Finance Lease, Right-of-Use Asset	1
Sales-type and Direct Financing Leases, Profit (Loss)	$ 4	$ 3

Leases Lease-related Assets and

Leases Lease-related Assets and Weighted Average Life and Discount Rate (Details) $ in Millions	Mar. 31, 2019USD ($)
Lease-related Assets [Abstract]
Operating Lease, Right-of-Use Asset	$ 244
Operating Lease, Liability	$ 252
Operating Lease, Weighted Average Remaining Lease Term	9 years 4 months 24 days
Finance Lease, Weighted Average Remaining Lease Term	1 year 1 month 7 days
Operating Lease, Weighted Average Discount Rate, Percent	3.20%
Finance Lease, Weighted Average Discount Rate, Percent	13.10%

Leases Lease Cost (Details)

Leases Lease Cost (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)
Leases cost [Abstract]
Operating Lease, Cost	$ 12
Variable Lease, Cost	13
Lease, Cost	$ 25

Leases Leases, Supplemental Cas

Leases Leases, Supplemental Cash Flow (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)
Leases, Supplement Cash Flow [Abstract]
Operating Cash Disbursement From Operating Leases	$ 10

Leases Lease Maturity Schedule

Leases Lease Maturity Schedule (Details) $ in Millions	Mar. 31, 2019USD ($)
Lease Maturity Schedule [Abstract]
Lease Liabilities, Maturity One Year	$ 41
Liabilities	45
Lease Liabilities, Maturity Year Three	39
Lease Liabilities, Maturity Year Four	35
Lease Liabilities, Maturity Year Five	31
Lease Liabilities, Maturity Year Thereafter	114
Lease Liabilities, Maturity	$ 305

Leases Operating Lease Maturity

Leases Operating Lease Maturity (Details) $ in Millions	Mar. 31, 2019USD ($)
Operation Lease Maturities [Abstract]
Lessor, Operating Lease, Payments to be Received, Remainder of Fiscal Year	$ 6
Lessor, Operating Lease, Payments to be Received	61
Operating Lease Maturities, Year Two	8
Operating Lease Maturities, Year Three	8
Operating Lease Maturities, Year Four	7
Operating Lease Maturities, Year Five	7
Lessor, Operating Lease, Payments to be Received, Thereafter	$ 25

Debt And Shareholders' Equity_2

Debt And Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	Mar. 31, 2019	Mar. 31, 2019	Mar. 31, 2018	Apr. 30, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt And Shareholders' Equity [Line Items]
Schedule of Long-term Debt Instruments [Table Text Block]		Long-term debt is summarized as follows: (In millions) March 31, December 31, 2018 Subordinated notes $ 87 $ 87 Senior notes 1,141 637 Total $ 1,228 $ 724
Subordinated Debt	$ 87	$ 87			$ 87
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		127	$ (128)
Stockholders' Equity [Abstract]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		(1)	$ 0
Senior Notes	$ 1,141	$ 1,141			637
Debt Instrument, Interest Rate Terms		0.0335
Entity Common Stock, Shares Outstanding	182,512,940	182,512,940		182,565,329
Common Stock, Par or Stated Value Per Share	$ 0.0010	$ 0.0010
Common Stock	$ 0	$ 0			0
Long-term Debt, Gross	1,228	$ 1,228			724
Stock Repurchased During Period, Shares		5,500,000	2,200,000
Stock Repurchased and Retired During Period, Value		$ 275	$ 115
Treasury Stock Acquired, Average Cost Per Share		$ 50.03	$ 53.46
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 275	$ 275
Common Stock, Terms of Conversion	1060000
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (122)	$ (122)	$ (267)		$ (250)	$ (139)
Warrant [Member]
Stockholders' Equity [Abstract]
Class of Warrant or Right, Outstanding	29,300,000	29,300,000
Warrant Exercise Price	$ 34.61	$ 34.61
Senior Notes [Member]
Stockholders' Equity [Abstract]
Senior Notes	$ 500	$ 500

Debt And Shareholders' Equity S

Debt And Shareholders' Equity Schedule of Long-Term Debt Instruments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Subordinated Debt	$ 87	$ 87
Senior Notes	1,141	637
Long-term Debt, Gross	$ 1,228	$ 724
Schedule of Long-term Debt Instruments [Table Text Block]	Long-term debt is summarized as follows: (In millions) March 31, December 31, 2018 Subordinated notes $ 87 $ 87 Senior notes 1,141 637 Total $ 1,228 $ 724

Debt And Shareholders' Equity_3

Debt And Shareholders' Equity (Schedule Of Changes In Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Debt And Shareholders' Equity [Line Items]
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax	$ 40	$ (41)
Income Tax Expense (Benefit)	61	70
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	127	(128)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	1	0
Beginning balance	(250)	(139)
Other comprehensive income (loss)	128	(128)
Ending balance	(122)	(267)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	2	(1)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	0	0
Other Comprehensive Income (Loss), Tax	42	(42)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Debt And Shareholders' Equity [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	122	(126)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0
Beginning balance	(228)	(114)
Other comprehensive income (loss)	122	(126)
Ending balance	(106)	(240)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Debt And Shareholders' Equity [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	5	(2)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	1	0
Beginning balance	(1)	(2)
Other comprehensive income (loss)	6	(2)
Ending balance	5	(4)
Accumulated Defined Benefit Plans Adjustment [Member]
Debt And Shareholders' Equity [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0
Beginning balance	(21)	(23)
Other comprehensive income (loss)	0	0
Ending balance	(21)	(23)
Interest Rate Contract [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Debt And Shareholders' Equity [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	(1)	0
Reclassification from AOCI, Current Period, Tax	(1)	0
Income Tax Expense (Benefit)	$ 0	$ 0

Commitments, Guarantees, And _3

Commitments, Guarantees, And Contingent Liabilities (Narrative) (Details) $ in Millions	Mar. 31, 2019USD ($)
Guarantor Obligations [Line Items]
Letters of credit, accrued liability	$ 4
Reserve for unfunded lending commitments	1
Deferred commitment fees	3
Minimum [Member]
Guarantor Obligations [Line Items]
Loss Contingency, Estimate of Possible Loss	0
Maximum [Member]
Guarantor Obligations [Line Items]
Loss Contingency, Estimate of Possible Loss	$ 50

Commitments, Guarantees, And _4

Commitments, Guarantees, And Contingent Liabilities (Schedule Of Guarantees Issued) (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Unused Commitments to Extend Credit	$ 21,632	$ 21,454
Commercial Letters Of Credit	27	18
Total Unfunded Lending Commitments	22,399	22,326
Financial [Member]
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Standby letters of credit	544	655
Performance [Member]
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Standby letters of credit	196	$ 199
Minimum [Member]
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Loss Contingency, Estimate of Possible Loss	0
Maximum [Member]
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Loss Contingency, Estimate of Possible Loss	$ 50

Revenue Recognition Revenue R_3

Revenue Recognition Revenue Recognitiion Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)States	Mar. 31, 2018USD ($)
Number of States in which Entity Operates | States	11
Other Service Charges, Commissions and Fees	$ 54	$ 55
Revenue Recognition [Member]
Interest and Fee Income, Loans, Consumer Installment, Credit Card	34	33
ATM Fees	2	2
Other Service Charges	3	4
Other Commissions and Fees	4	5
Other Service Charges, Commissions and Fees	$ 43	$ 44

Revenue Recognition Other Servi

Revenue Recognition Other Service charges, commissions and fees (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Other Service charges, commissions and fees [Line Items]
Other Service Charges, Commissions and Fees	$ 54	$ 55
Revenue Recognition [Member]
Other Service charges, commissions and fees [Line Items]
Other Service Charges	3	4
Other Service Charges, Commissions and Fees	$ 43	$ 44

Revenue Recognition Revenue by

Revenue Recognition Revenue by Operation Segments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Service Charges and Fees on Deposit Accounts	$ 40	$ 42
Noninterest income, Customer-related Fees	120	123
Noninterest Income	132	138
Other Service Charges, Commissions and Fees	54	55
Wealth Management and Trust Income	13	12
Interest Income (Expense), Net	576	542
Zions Bank [Member]
Segment Reporting Information [Line Items]
Service Charges and Fees on Deposit Accounts	13	15
Noninterest income, Customer-related Fees	32	34
Other non-interest income (non-customer related)	1	1
Noninterest Income	33	35
Gains (Losses) on Sales of Other Real Estate	1	1
Other Service Charges, Commissions and Fees	17	16
Wealth Management and Trust Income	4	4
Brokerage Commissions Revenue	1	1
Other Noninterest Income From Contracts With Customers	0	0
Total non-interest income from contracts with customers (ASC 606)	35	36
Other non-interest income (Non-ASC 606 customer related)	(3)	(2)
Interest Income (Expense), Net	180	167
Revenues	214	203
National Bank Of Arizona [Member]
Segment Reporting Information [Line Items]
Service Charges and Fees on Deposit Accounts	3	3
Noninterest income, Customer-related Fees	9	8
Other non-interest income (non-customer related)	1	1
Noninterest Income	10	9
Gains (Losses) on Sales of Other Real Estate	0	0
Other Service Charges, Commissions and Fees	3	2
Wealth Management and Trust Income	0	1
Brokerage Commissions Revenue	0	0
Other Noninterest Income From Contracts With Customers	0	0
Total non-interest income from contracts with customers (ASC 606)	6	6
Other non-interest income (Non-ASC 606 customer related)	3	2
Interest Income (Expense), Net	60	53
Revenues	70	62
Nevada State Bank [Member]
Segment Reporting Information [Line Items]
Service Charges and Fees on Deposit Accounts	4	4
Noninterest income, Customer-related Fees	10	10
Other non-interest income (non-customer related)	0	0
Noninterest Income	10	10
Gains (Losses) on Sales of Other Real Estate	0	0
Other Service Charges, Commissions and Fees	3	3
Wealth Management and Trust Income	1	1
Brokerage Commissions Revenue	0	0
Other Noninterest Income From Contracts With Customers	0	0
Total non-interest income from contracts with customers (ASC 606)	8	8
Other non-interest income (Non-ASC 606 customer related)	2	2
Interest Income (Expense), Net	40	35
Revenues	50	45
Vectra Bank Colorado [Member]
Segment Reporting Information [Line Items]
Service Charges and Fees on Deposit Accounts	2	2
Noninterest income, Customer-related Fees	5	6
Other non-interest income (non-customer related)	1	0
Noninterest Income	6	6
Gains (Losses) on Sales of Other Real Estate	0	0
Other Service Charges, Commissions and Fees	2	3
Wealth Management and Trust Income	0	0
Brokerage Commissions Revenue	0	0
Other Noninterest Income From Contracts With Customers	0	0
Total non-interest income from contracts with customers (ASC 606)	4	5
Other non-interest income (Non-ASC 606 customer related)	1	1
Interest Income (Expense), Net	36	32
Revenues	42	38
Commerce Bank Of Washington [Member]
Segment Reporting Information [Line Items]
Service Charges and Fees on Deposit Accounts	0	0
Noninterest income, Customer-related Fees	1	1
Other non-interest income (non-customer related)	0	0
Noninterest Income	1	1
Gains (Losses) on Sales of Other Real Estate	0	0
Other Service Charges, Commissions and Fees	1	1
Wealth Management and Trust Income	0	0
Brokerage Commissions Revenue	0	0
Other Noninterest Income From Contracts With Customers	0	0
Total non-interest income from contracts with customers (ASC 606)	1	1
Other non-interest income (Non-ASC 606 customer related)	0	0
Interest Income (Expense), Net	14	11
Revenues	15	12
Other Segment [Member]
Segment Reporting Information [Line Items]
Service Charges and Fees on Deposit Accounts	0	1
Noninterest income, Customer-related Fees	8	16
Other non-interest income (non-customer related)	11	8
Noninterest Income	19	24
Gains (Losses) on Sales of Other Real Estate	0	0
Other Service Charges, Commissions and Fees	1	6
Wealth Management and Trust Income	4	3
Brokerage Commissions Revenue	2	3
Other Noninterest Income From Contracts With Customers	0	0
Total non-interest income from contracts with customers (ASC 606)	7	13
Other non-interest income (Non-ASC 606 customer related)	1	3
Interest Income (Expense), Net	(23)	(14)
Revenues	(4)	10
Amegy Corporation [Member]
Segment Reporting Information [Line Items]
Service Charges and Fees on Deposit Accounts	11	10
Noninterest income, Customer-related Fees	35	30
Other non-interest income (non-customer related)	(1)	2
Noninterest Income	34	32
Gains (Losses) on Sales of Other Real Estate	0	0
Other Service Charges, Commissions and Fees	9	8
Wealth Management and Trust Income	3	2
Brokerage Commissions Revenue	(1)	(2)
Other Noninterest Income From Contracts With Customers	0	0
Total non-interest income from contracts with customers (ASC 606)	22	18
Other non-interest income (Non-ASC 606 customer related)	13	12
Interest Income (Expense), Net	131	127
Revenues	165	159
California Bank Trust [Member]
Segment Reporting Information [Line Items]
Service Charges and Fees on Deposit Accounts	7	7
Noninterest income, Customer-related Fees	20	18
Other non-interest income (non-customer related)	(1)	3
Noninterest Income	19	21
Gains (Losses) on Sales of Other Real Estate	0	0
Other Service Charges, Commissions and Fees	7	5
Wealth Management and Trust Income	1	1
Brokerage Commissions Revenue	1	1
Other Noninterest Income From Contracts With Customers	0	0
Total non-interest income from contracts with customers (ASC 606)	16	14
Other non-interest income (Non-ASC 606 customer related)	4	4
Interest Income (Expense), Net	138	131
Revenues	157	152
Consolidated Entities [Member]
Segment Reporting Information [Line Items]
Service Charges and Fees on Deposit Accounts	40	42
Noninterest income, Customer-related Fees	120	123
Other non-interest income (non-customer related)	12	15
Noninterest Income	132	138
Gains (Losses) on Sales of Other Real Estate	1	1
Other Service Charges, Commissions and Fees	43	44
Wealth Management and Trust Income	13	12
Brokerage Commissions Revenue	3	3
Other Noninterest Income From Contracts With Customers	0	0
Total non-interest income from contracts with customers (ASC 606)	99	101
Other non-interest income (Non-ASC 606 customer related)	21	22
Interest Income (Expense), Net	576	542
Revenues	$ 709	$ 681

Retirement Plans (Schedule Of N

Retirement Plans (Schedule Of Net Periodic Benefit Cost (Credit) For Pension And Postretirement Plans) (Details) - Pension Plan [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 1	$ 1
Expected return on plan assets	(2)	(3)
Amortization of net actuarial (gain) loss	1	0
Net periodic benefit cost (credit)	0	(1)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	$ 0	$ 1

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Income Tax Contingency [Line Items]
Effective Income Tax Rate Reconciliation, Percent	22.30%	22.70%
Deferred Tax Assets, Net	$ 73		$ 130

Net Earnings per Common Share_2

Net Earnings per Common Share Basic and diluted net earnings per common share based on the weighted average outstanding shares (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 213	$ 238
Dividends	64	47
Undistributed Earnings, Basic	149	191
Undistributed Earnings Applicable to Nonvested Shares	1	1
Undistributed Earnings (Loss) Available to Common Shareholders, Diluted	148	190
Distributed Earnings	$ 56	$ 39
Weighted Average Number of Shares Outstanding, Basic	184,767	196,722
Dilutive Effect of Common Stock Warrants	9,739	12,382
Dilutive Effect of Stock Options	735	1,139
Earnings Per Share, Basic	$ 1.10	$ 1.16
Net Income (Loss) Available to Common Stockholders, Diluted	$ 204	$ 229
Weighted Average Number of Shares Outstanding, Diluted	195,241	210,243
Earnings Per Share, Diluted	$ 1.04	$ 1.09

Net Earnings per Common Share_3

Net Earnings per Common Share Weighted average shares of stock awards that were anti-dilutive and not included in the calculation of diluted earnings per share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1,423	1,757

Operating Segment Information_2

Operating Segment Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)Branches	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)
Segment Reporting Information [Line Items]
Number of community regional banks operating in distinct geographical areas	7
Interest Income (Expense), Net	$ 576	$ 542
Provision for Loan and Lease Losses	2	(40)
Interest Income (Expense), after Provision for Loan Loss	572	589
Noninterest Income, Other Operating Income	2	4
Noninterest Expense	430	419
Income (Loss) from Continuing Operations before Income Taxes, Domestic	$ 274	308
Number of Branches | Branches	433
Investment Securities Gross Unrealized Losses Less Than 12 Months	$ 15		$ 40
Investment Securities Estimated Fair Value Less Than 12 Months	1,256		2,858
Investment Securities Gross Unrealized Losses 12 Months or More	187		297
Investment Securities Estimated Fair Value 12 Months or More	9,576		9,375
Investment Securities Gross Unrealized Losses Total	202		337
Investment Securities Estimated Fair Value Total	10,832		12,233
Zions Bank [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	180	167
Provision for Loan and Lease Losses	11	(2)
Interest Income (Expense), after Provision for Loan Loss	169	169
Noninterest Income, Other Operating Income	33	35
Noninterest Expense	118	113
Income (Loss) from Continuing Operations before Income Taxes, Domestic	84	91
Average Loans And Leases	12,939	12,453
Average Deposits	15,524	15,712
Amegy Corporation [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	131	127
Provision for Loan and Lease Losses	(15)	(53)
Interest Income (Expense), after Provision for Loan Loss	146	180
Noninterest Income, Other Operating Income	34	32
Noninterest Expense	88	87
Income (Loss) from Continuing Operations before Income Taxes, Domestic	92	125
Average Loans And Leases	11,861	11,370
Average Deposits	11,441	10,816
National Bank Of Arizona [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	60	53
Provision for Loan and Lease Losses	3	2
Interest Income (Expense), after Provision for Loan Loss	57	51
Noninterest Income, Other Operating Income	10	9
Noninterest Expense	39	38
Income (Loss) from Continuing Operations before Income Taxes, Domestic	28	22
Average Loans And Leases	4,749	4,543
Average Deposits	4,894	4,783
Zions Bank [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	14	11
Provision for Loan and Lease Losses	0	1
Interest Income (Expense), after Provision for Loan Loss	14	10
Noninterest Income, Other Operating Income	1	1
Noninterest Expense	6	6
Income (Loss) from Continuing Operations before Income Taxes, Domestic	9	5
Average Loans And Leases	1,110	1,084
Average Deposits	1,075	1,073
California Bank Trust [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	138	131
Provision for Loan and Lease Losses	3	2
Interest Income (Expense), after Provision for Loan Loss	135	129
Noninterest Income, Other Operating Income	19	21
Noninterest Expense	82	77
Income (Loss) from Continuing Operations before Income Taxes, Domestic	72	73
Average Loans And Leases	10,574	9,929
Average Deposits	11,243	11,119
Nevada State Bank [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	40	35
Provision for Loan and Lease Losses	(1)	0
Interest Income (Expense), after Provision for Loan Loss	41	35
Noninterest Income, Other Operating Income	10	10
Noninterest Expense	36	36
Income (Loss) from Continuing Operations before Income Taxes, Domestic	15	9
Average Loans And Leases	2,500	2,348
Average Deposits	4,329	4,223
Vectra Bank Colorado [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	36	32
Provision for Loan and Lease Losses	4	3
Interest Income (Expense), after Provision for Loan Loss	32	29
Noninterest Income, Other Operating Income	6	6
Noninterest Expense	28	27
Income (Loss) from Continuing Operations before Income Taxes, Domestic	10	8
Average Loans And Leases	3,055	2,794
Average Deposits	2,821	2,711
Other Segment [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	(23)	(14)
Provision for Loan and Lease Losses	(1)	0
Interest Income (Expense), after Provision for Loan Loss	(22)	(14)
Noninterest Income, Other Operating Income	19	24
Noninterest Expense	33	35
Income (Loss) from Continuing Operations before Income Taxes, Domestic	(36)	(25)
Average Loans And Leases	383	343
Average Deposits	$ 2,589	1,557
ARIZONA | National Bank Of Arizona [Member]
Segment Reporting Information [Line Items]
Number of Branches | Branches	58
NEVADA | Nevada State Bank [Member]
Segment Reporting Information [Line Items]
Number of Branches | Branches	50
Utah [Member] | Zions Bank [Member]
Segment Reporting Information [Line Items]
Number of Branches | Branches	98
Idaho [Member] | Zions Bank [Member]
Segment Reporting Information [Line Items]
Number of Branches | Branches	23
WYOMING | Zions Bank [Member]
Segment Reporting Information [Line Items]
Number of Branches | Branches	1
Colorado [Member] | Vectra Bank Colorado [Member]
Segment Reporting Information [Line Items]
Number of Branches | Branches	36
New Mexico [Member] | Vectra Bank Colorado [Member]
Segment Reporting Information [Line Items]
Number of Branches | Branches	1
WASHINGTON | Zions Bank [Member]
Segment Reporting Information [Line Items]
Number of Branches | Branches	1
OREGON | Zions Bank [Member]
Segment Reporting Information [Line Items]
Number of Branches | Branches	1
TEXAS | Amegy Corporation [Member]
Segment Reporting Information [Line Items]
Number of Branches | Branches	74
CALIFORNIA | California Bank And Trust [Member]
Segment Reporting Information [Line Items]
Number of Branches | Branches	90
Consolidated Entities [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	$ 576	542
Provision for Loan and Lease Losses	4	(47)
Interest Income (Expense), after Provision for Loan Loss	572	589
Noninterest Income, Other Operating Income	132	138
Noninterest Expense	430	419
Income (Loss) from Continuing Operations before Income Taxes, Domestic	274	308
Average Loans And Leases	47,171	44,864
Average Deposits	53,916	$ 51,994
Available-for-sale Securities [Member]
Segment Reporting Information [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	15		39
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	1,232		2,772
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	181		287
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	9,161		8,937
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	196		326
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	10,393		11,709
Agency Securities [Member]
Segment Reporting Information [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0		2
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	46		245
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	11		17
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	994		913
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	11		19
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,040		1,158
Agency Guaranteed Mortgage Backed Securities [Member]
Segment Reporting Information [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	2		16
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	270		1,081
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	134		224
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	6,799		6,661
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	136		240
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	7,069		7,742
Small Business Administration Loan Backed Securities [Member]
Segment Reporting Information [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	13		19
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	876		1,180
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	30		28
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	898		711
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	43		47
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,774		1,891
US States and Political Subdivisions Debt Securities [Member]
Segment Reporting Information [Line Items]
Debt Securities, Held-to-maturity, Unrealized Loss Position, Fair Value	439		524
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	6		10
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0		1
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value	24		86
Debt Securities, Held-to-maturity, Continuous Unrealized Loss Position, 12 Months or Longer, Fair Value	415		438
Debt Securities, Held-to-maturity, Unrealized Loss Position, Accumulated Loss	6		11
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0		2
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	40		266
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	3		14
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	458		641
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	3		16
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	498		907
Available-for-sale, Unrealized losses, Other [Member]
Segment Reporting Information [Line Items]
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	0		0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	3		4
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	12		11
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss	3		4
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	$ 12		$ 11