Zions Bancorporation, National Association (ZION) 10-Q 8 May 17 2017 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 28, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Trading Symbol	zion
Entity Registrant Name	ZIONS BANCORPORATION /UT/
Entity Central Index Key	109,380
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		202,629,299

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Held-to-maturity, fair value	$ 803	$ 850
ASSETS
Cash and due from banks	566	737
Money market investments:
Interest-bearing deposits	1,761	1,411
Federal funds sold and security resell agreements	363	568
Investment securities:
Held-to-maturity, at amortized cost (approximate fair value $803 and $850)	815	868
Available-for-sale, at fair value	15,606	13,372
Trading account, at fair value	40	115
Marketable securities, total	16,461	14,355
Loans held for sale	128	172
Loans held for investment, net allowance
Loans and leases, net of unearned income and fees	42,742	42,649
Loans and Leases Receivable, Allowance	544	567
Loans held for investment, net of allowance	42,198	42,082
Other noninterest-bearing investments	973	884
Premises, equipment and software, net	1,047	1,020
Goodwill	1,014	1,014
Core deposit and other intangibles	7	8
Other real estate owned	3	4
Other assets	942	984
Total assets	65,463	63,239
LIABILITIES AND SHAREHOLDERS' EQUITY
Noninterest-bearing demand	24,410	24,115
Interest-bearing:
Savings and money market	26,071	26,364
Time	2,994	2,757
Foreign	0	0
Total deposits	53,475	53,236
Federal funds and other short-term borrowings	3,137	827
Long-term debt	383	535
Reserve for unfunded lending commitments	60	65
Other liabilities	678	942
Total liabilities	57,733	55,605
Shareholders' equity:
Preferred stock, without par value, authorized 4,400,000 shares	710	710
Common stock, without par value; authorized 350,000 shares; issued and outstanding 202,595 and 203,085 shares	4,696	4,725
Retained earnings	2,435	2,321
Accumulated other comprehensive income (loss)	(111)	(122)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	7,730	7,634
Total liabilities and shareholders' equity	$ 65,463	$ 63,239

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Held-to-maturity, fair value	$ 803	$ 850
Preferred stock, authorized shares	4,400,000	4,400,000
Common stock, authorized shares	350,000,000	350,000,000
Common stock, issued shares	202,595,000	203,085,000
Common stock, outstanding shares	202,595,000	203,085,000

Consolidated Statements Of Inco

Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Interest income:
Interest and fees on loans	$ 433	$ 421
Interest on money market investments	4	7
Interest on Securities	78	47
Interest on securities:
Total interest income	515	475
Interest expense:
Interest on deposits	13	12
Interest on short- and long-term borrowings	13	10
Total interest expense	26	22
Net interest income	489	453
Provision for loan losses	23	42
Net interest income after provision for loan losses	466	411
Noninterest income:
Service charges and fees on deposit accounts	42	41
Other service charges, commissions and fees	49	49
Wealth management income	10	8
Loan sales and servicing income	7	8
Capital markets and foreign exchange	7	6
Noninterest income, Customer-related Fees	115	112
Investment Income, Nonoperating	12	5
Gain (Loss) on Sale of Securities, Net	5	0
Other	0	0
Total noninterest income	132	117
Noninterest expense:
Salaries and employee benefits	262	258
Occupancy, net	33	30
Furniture, equipment and software, net	32	32
Other real estate expense, net	0	(1)
Credit-related expense	8	6
Provision for unfunded lending commitments	5	6
Professional and legal services	14	12
Advertising	5	6
FDIC premiums	12	7
Amortization of core deposit and other intangibles	2	2
Other	51	50
Total noninterest expense	414	396
Income before Income taxes	184	132
Income taxes	45	41
Net income	139	91
Dividends on preferred stock	(10)	(12)
Preferred Stock Redemption	0	0
Net earnings applicable to common shareholders	$ 129	$ 79
Weighted average common shares outstanding during the period:
Basic shares (in thousands)	202,347	203,967
Diluted shares (in thousands)	210,405	204,096
Net earnings per common share:
Basic	$ 0.63	$ 0.38
Diluted	$ 0.61	$ 0.38

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Net income for the period	$ 139	$ 91
Other comprehensive income, net of tax:
Unrealized holding gains on investment securities	12	32
Net unrealized gains on other noninterest-bearing investments	1	1
Net unrealized holding gains (losses) on derivative instruments	(1)	13
Reclassification adjustment for increase in interest income recognized in earnings on derivatives instruments	(1)	(2)
Pension and Postretirement	0	(1)
Other comprehensive income	11	43
Comprehensive income	$ 150	$ 134

Consolidated Statements Of Chan

Consolidated Statements Of Changes In Shareholders' Equity - USD ($) $ in Millions	Total	Preferred Stock [Member]	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 7,507	$ 828	$ 4,767	$ 1,967	$ (55)
Balance (in shares) at Dec. 31, 2015			204,417,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income for the period	91			91
Other comprehensive income, net of tax	43				43
Net activity under employee plans and related tax benefits	11		$ 11
Net activity under employee plans and related tax benefits, shares			127,000
Dividends on preferred stock	(12)			(12)
Dividends on common stock	(13)			(13)
Change in deferred compensation	(2)			(2)
Balance (in shares) at Mar. 31, 2016			204,544,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	7,625	828	$ 4,778	2,031	(12)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	7,634	710	4,725	2,321	(122)
Stock Repurchased and Retired During Period, Value	$ (45)		$ (45)
Stock Repurchased During Period, Shares	1,100,000		(1,060,000)
Balance (in shares) at Dec. 31, 2016	203,085,000		203,085,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income for the period	$ 139			139
Other comprehensive income, net of tax	11				11
Net activity under employee plans and related tax benefits	16		$ 16
Net activity under employee plans and related tax benefits, shares			570,000
Dividends on preferred stock	(10)			(10)
Dividends on common stock	$ (15)			(15)
Increase (Decrease) in Deferred Compensation				0
Balance (in shares) at Mar. 31, 2017	202,595,000		202,595,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 7,730	$ 710	$ 4,696	$ 2,435	$ (111)

Consolidated Statements Of Cha7

Consolidated Statements Of Changes In Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Dividends on common stock, per share	$ 0.08	$ 0.06

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Real Estate Owned, Transfer to Real Estate Owned	$ 2	$ 6
Transfer of Portfolio Loans and Leases to Held-for-sale	(35)	(2)
Available for sale securities purchased, not settled	56	0
Held to Maturity Securities Purchased, Not Settled	31	0
CASH FLOWS FROM OPERATING ACTIVITIES
Net income for the period	139	91
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses	18	36
Depreciation and amortization	37	25
Share-based Compensation	12	11
Deferred income tax expense (benefit)	13	(5)
Net decrease (increase) in trading securities	76	(18)
Net decrease (increase) in loans held for sale	36	39
Change in other liabilities	42	18
Change in other assets	21	7
Other, net	(14)	3
Net cash provided by operating activities	380	207
CASH FLOWS FROM INVESTING ACTIVITIES
Net decrease (increase) in money market investments	(145)	2,102
Proceeds from maturities and paydowns of investment securities held-to-maturity	91	22
Purchases of investment securities held-to-maturity	(7)	(108)
Proceeds from sales, maturities, and paydowns of investment securities available-for-sale	530	2,098
Purchases of investment securities available-for-sale	(3,113)	(3,123)
Net change in loans held for investment	(117)	(793)
Net change in other noninterest-bearing investments	(74)	(12)
Purchases of premises and equipment	(50)	(40)
Proceeds from sales of other real estate owned	3	4
Other, net	2	2
Net cash provided by (used in) investing activities	(2,880)	152
CASH FLOWS FROM FINANCING ACTIVITIES
Net increase (decrease) in deposits	241	(486)
Net change in short-term funds borrowed	2,311	(115)
Repayments of long-term debt	(153)	(11)
Proceeds from Issuance of Common Stock	9	1
Dividends paid on common and preferred stock	(29)	(27)
Company common stock repurchased and retired	(50)	(1)
Net cash provided by (used in) financing activities	2,329	(639)
Net decrease in cash and due from banks	(171)	(280)
Cash and due from banks at beginning of period	737	798
Cash and due from banks at end of period	566	518
Cash paid for interest	22	18
Net refunds received for income taxes	$ (6)	$ 0

Basis of Presentaion

Basis of Presentaion	3 Months Ended
	Mar. 31, 2017
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 (“the Parent”) and its majority-owned subsidiaries (collectively “the Company,” “Zions,” “we,” “our,” “us”) have been prepared in accordance with 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 (“EITF”). In certain cases, ASUs are issued jointly with International Financial Reporting Standards (“IFRS”). Operating results for the three months ended March 31, 2017 and 2016 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, 2016 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 Company’s 2016 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 (“the Parent”) is a financial holding company headquartered in Salt Lake City, Utah, which owns and operates a commercial bank. The Parent and its subsidiaries (collectively “the Company”) provide a full range of banking and related services in 11 Western and Southwestern states through seven separately managed and branded units as follows: Zions Bank, in Utah, Idaho and Wyoming; California Bank & Trust (“CB&T”); Amegy Bank (“Amegy”), in Texas; 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 (“TCBO”) in Oregon. The Parent also owns and operates certain nonbank subsidiaries that engage in financial services.

Certain Recent Accounting Prono

Certain Recent Accounting Pronouncements (Notes)	3 Months Ended
	Mar. 31, 2017
Certain Recent Accounting Pronouncements [Abstract]
Certain Recent Accounting Pronouncements [Text Block]	RECENT ACCOUNTING PRONOUNCEMENTS Standard Description Date of adoption Effect on the financial statements or other significant matters Standards not yet adopted by the Company ASU 2014-09, Revenue from Contracts with Customers (Topic 606) and subsequent related ASUs The core principle of the new guidance is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The banking industry does not expect significant changes because major sources of revenue are from financial instruments that have been excluded from the scope of the new standard, (including loans, derivatives, debt and equity securities, etc.). However, these new standards affect other fees charged by banks, such as asset management fees, credit card interchange fees, deposit account fees, etc. Adoption may be made on a full retrospective basis with practical expedients, or on a modified retrospective basis with a cumulative effect adjustment. January 1, 2018 Approximately 85% of our revenue, including all of our net interest income and a portion of our noninterest income, is out of scope of the guidance. The contracts that are in scope of the guidance are primarily related to service charges and fees on deposit accounts, wealth management income, and other service charges, commissions and fees. We have created an implementation team that is analyzing the individual contracts in scope to determine if our current accounting will change. This review is expected to be completed in the second quarter of 2017. We plan to adopt this guidance using the modified retrospective transition method. ASU 2016-01, Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities The standard provides revised accounting guidance related to the accounting for and reporting of financial instruments. Some of the main provisions include: – Changes in instrument-specific credit risk for financial liabilities that are measured under the fair value option would be recognized in other comprehensive income (“OCI”). January 1, 2018 We do not expect this guidance will have a material impact on the Company’s financial statements. We do not have a significant amount of equity securities classified as available-for-sale (“AFS”). Additionally, we do not have any financial liabilities accounted for under the fair value option. Therefore, the transition adjustment upon adoption of this guidance is not expected to be material. We have formed a working group to evaluate the fair value measurements of financial instruments for disclosure purposes. ASU 2016-02, Leases (Topic 842) The standard requires that a lessee recognize assets and liabilities for leases with lease terms of more than 12 months. For leases with a term of 12 months or less, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. The recognition, measurement, and presentation of expenses and cash flows arising from a lease by a lessee primarily will depend on its classification as a finance or operating lease. However, the standard will require both types of leases to be recognized on the balance sheet. It also requires disclosures to better understand the amount, timing, and uncertainty of cash flows arising from leases. These disclosures include qualitative and quantitative requirements, providing additional information about the amounts recorded in the financial statements. January 1, 2019 We are currently evaluating the potential impact of this guidance on the Company’s financial statements. As of December 31, 2016, the Company had minimum noncancelable net operating lease payments of $275 million that are being evaluated. The implementation team is working on gathering all key lease data elements to meet the requirements of the new guidance. Additionally, we are implementing new lease software that will accommodate the new accounting requirements. Standard Description Date of adoption Effect on the financial statements or other significant matters Standards not yet adopted by the Company (continued) 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 to be amortized to the earliest call date. The update does not change the accounting for securities held at a discount. January 1, 2019 Our initial analysis suggests this guidance will not have a material impact on the Company’s financial statements, but we will continue to monitor its impact as we move closer to implementation. ASU 2016-13, Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments The standard significantly changes how entities will measure credit losses for most financial assets and certain other instruments that are not measured at fair value through net income. 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 AFS debt securities to be recorded through an allowance for credit losses (“ACL”) rather than a reduction of the carrying amount. It also changes the accounting for purchased credit-impaired debt securities and loans. The standard retains many of the current disclosure requirements in current GAAP and expands certain disclosure requirements. Early adoption of the guidance is permitted as of January 1, 2019. January 1, 2020 We have formed an implementation team led jointly by Credit and the Corporate Controller’s group, that also includes other lines of business and functions within the Company. The implementation team is working on developing models that can meet the requirements of the new guidance. While we expect this standard will have a material impact on the Company’s financial statements, we are still in process of conducting our evaluation. ASU 2017-04, Intangibles – Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment The standard eliminates the requirement to calculate the implied fair value of goodwill (i.e. Step 2 of the current goodwill impairment test) to measure a goodwill impairment charge. Instead, entities would record an impairment charge based on the excess of a reporting unit’s carrying amount over its fair value (i.e., measure the charge based on Step 1 of the current guidance). The standard does not change the guidance on completing Step 1 of the goodwill impairment test. The standard also continues to allow entities to perform the optional qualitative goodwill impairment assessment before determining whether to proceed to Step 1. The standard is effective for the Company 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 Company’s financial statements since the fair values of our reporting units were not lower than their respective carrying amounts at the time of our goodwill impairment analysis for 2016. Standards adopted by the Company ASU 2016-09, Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting The standard requires entities to recognize the income tax effects of share-based awards in the income statement when the awards vest or are settled (i.e. the additional paid-in capital pools will be eliminated). The standard provides an entity the option to make an entity-wide accounting policy election to either estimate the number of awards that are expected to vest or account for forfeitures when they occur. The standard also requires that excess tax benefits be reflected in the operating section of the statement of cash flows rather than the investing section and to make an election to adopt this requirement either on a retrospective or prospective basis. January 1, 2017 Upon adoption of this ASU, there was no material impact from the cumulative effect adjustment to retained earnings. In the first quarter of 2017 the application of the guidance resulted in a net tax benefit of $4 million. We have elected to account for forfeitures when they occur and to reflect excess tax benefits in the operating section of the statement of cash flows on a prospective basis.

Fair Value

Fair Value	3 Months Ended
	Mar. 31, 2017
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. To measure fair value, a hierarchy has been established that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs. This hierarchy uses three levels of inputs to measure the fair value of assets and liabilities as follows: Level 1 – Quoted prices in active markets for identical assets or liabilities in active markets that the Company has the ability to access; Level 2 – Observable inputs other than Level 1 including quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in less active markets, observable inputs other than quoted prices that are used in the valuation of an asset or liability, and inputs that are derived principally from or corroborated by observable market data by correlation or other means; and Level 3 – Unobservable inputs supported by little or no market activity for financial instruments whose value is determined by pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation. The level in the fair value hierarchy within which the fair value measurement is classified is determined based on the lowest level input that is significant to the fair value measure in its entirety. Market activity is presumed to be orderly in the absence of evidence of forced or disorderly sales, although such sales may still be indicative of fair value. Applicable accounting guidance precludes the use of blockage factors or liquidity adjustments due to the quantity of securities held by an entity. We use fair value to measure certain assets and liabilities on a recurring basis when fair value is the primary measure for accounting. Fair value is used on a nonrecurring basis to measure certain assets when adjusting carrying values, such as the application of lower of cost or fair value accounting, including recognition of impairment on assets. Fair value is also used when providing required disclosures for certain financial instruments. Fair Value Policies and Procedures We have various policies, processes and controls in place to ensure that fair values are reasonably developed, reviewed and approved for use. These include a Securities Valuation Committee comprised of executive management appointed by the Board of Directors. The Securities Valuation Committee reviews and approves on a quarterly basis the key components of fair value estimation, including critical valuation assumptions for Level 3 modeling. A Model Risk Management Group conducts model validations, including internal models, and sets policies and procedures for revalidation, including the timing of revalidation. Third-Party Service Providers We use a third-party pricing service to measure fair value for approximately 92% of our AFS Level 2 securities. Fair value measurements for other AFS Level 2 securities generally use certain inputs corroborated by market data and include standard discounted cash flow analysis. For Level 2 securities, the third-party pricing service provides documentation on an ongoing basis that presents market corroborative data, including detail pricing information and market reference data. The documentation includes benchmark yields, reported trades, broker-dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, and reference data, including information from the vendor trading platform. We review, test and validate this information as appropriate. Absent observable trade data, we do not adjust prices from our third-party sources. The following describes the hierarchy designations, valuation methodologies, and key inputs to measure fair value on a recurring basis for designated financial instruments: Available-for-Sale U.S. Treasury, Agencies and Corporations U.S. Treasury securities are measured under Level 1 using quoted market prices when available. U.S. agencies and corporations are measured under Level 2 generally using the previously discussed third party pricing service. Municipal Securities Municipal securities are measured under Level 2 generally using the third-party pricing service or an internal model. Valuation inputs include Baa municipal curves, as well as Federal Home Loan Bank (“FHLB”) and LIBOR swap curves. Our valuation methodology for non-rated municipal securities changed at year-end to utilize more observable inputs, primarily municipal market yield curves, compared to our previous valuation method. The resulting values were determined to be Level 2. Money Market Mutual Funds and Other Money market mutual funds and other securities are measured under Level 1 or Level 2. For Level 1, quoted market prices are used which may include net asset values (“NAVs”) or their equivalents. Level 2 valuations generally use quoted prices for similar securities. Trading Account Securities in the trading account are generally measured under Level 2 using third party pricing service providers as described previously. Bank-Owned Life Insurance Bank-owned life insurance (“BOLI”) is measured under Level 2 according to cash surrender values (“CSVs”) of the insurance policies that are provided by a third-party service. Nearly all policies are general account policies with CSVs based on the Company’s claims on the assets of the insurance companies. The insurance companies’ investments include predominantly fixed income securities consisting of investment-grade corporate bonds and various types of mortgage instruments. Management regularly reviews its BOLI investment performance, including concentrations among insurance providers. Private Equity Investments Private equity investments are generally measured under Level 3. Certain investments that have converted to being publicly traded are measured under Level 1. The majority of these private equity investments are held in Zions’ Small Business Investment Company and are early stage venture investments. The fair value measurements of these investments are updated at least on a quarterly basis, including whenever a new round of financing occurs. Certain of these investments are measured using multiples of operating performance. The fair value measurements of private equity investments are reviewed on a quarterly basis by the Securities Valuation Committee. The Equity Investments Committee, consisting of executives familiar with the investments, reviews periodic financial information, including audited financial statements when available. Certain valuation analytics may be employed that include current and projected financial performance, recent financing activities, economic and market conditions, market comparables, market liquidity, sales restrictions, and other factors. A significant change in the expected performance of the individual investment would result in a change in the fair value measurement of the investment. The amount of unfunded commitments to invest is disclosed in Note 9 . Certain restrictions apply for the redemption of these investments and certain investments are prohibited by the Volcker Rule. See discussions in Notes 5 and 9 . Agriculture Loan Servicing This asset results from our servicing of agriculture loans approved and funded by Federal Agricultural Mortgage Corporation (“FAMC”). We provide this servicing under an agreement with FAMC for loans they own. The asset’s fair value represents our projection of the present value of future cash flows measured under Level 3 using discounted cash flow methodologies. Interest-Only Strips Interest-only strips are created as a by-product of the securitization process. When the guaranteed portions of small business (“SBA”) 7(a) loans are pooled, interest-only strips may be created in the pooling process. The asset’s fair value represents our projection of the present value of future cash flows measured under Level 3 using discounted cash flow methodologies. Deferred Compensation Plan Assets and Obligations Invested assets in the deferred compensation plan consist of shares of registered investment companies. These mutual funds are valued under Level 1 at quoted market prices, which represents the NAV of shares held by the plan at the end of the period. Derivatives Derivatives are measured according to their classification as either exchange-traded or over-the-counter. Exchange-traded derivatives consist of foreign currency exchange contracts measured under Level 1 because they are traded in active markets. Over-the-counter derivatives, including those for customers, consist of interest rate swaps and options. These derivatives are measured under Level 2 using third party services. Observable market inputs include yield curves (the LIBOR swap curve and relevant overnight index swap curves), foreign exchange rates, commodity prices, option volatilities, counterparty credit risk, and other related data. Credit valuation adjustments are required to reflect nonperformance risk for both the Company and the respective counterparty. These adjustments are determined generally by applying a credit spread to the total expected exposure of the derivative. Securities Sold, Not Yet Purchased Securities sold, not yet purchased, included in “Federal funds and other short-term borrowings” on the balance sheet, are measured under Level 1 using quoted market prices. If not available, quoted prices under Level 2 for similar securities are used. 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, 2017 Level 1 Level 2 Level 3 Total ASSETS Investment securities: Available-for-sale: U.S. Treasury, agencies and corporations $ — $ 14,163 $ — $ 14,163 Municipal securities 1,285 1,285 Other debt securities 24 24 Money market mutual funds and other 133 1 134 133 15,473 — 15,606 Trading account 40 40 Other noninterest-bearing investments: Bank-owned life insurance 499 499 Private equity investments 1 15 78 93 Other assets: Agriculture loan servicing and interest-only strips 20 20 Deferred compensation plan assets 95 95 Derivatives: Interest rate swaps and forwards 2 2 Interest rate swaps for customers 44 44 Foreign currency exchange contracts 9 9 9 46 — 55 $ 252 $ 16,058 $ 98 $ 16,408 LIABILITIES Securities sold, not yet purchased $ 133 $ — $ — $ 133 Other liabilities: Deferred compensation plan obligations 95 95 Derivatives: Interest rate swaps and forwards 4 4 Interest rate swaps for customers 45 45 Foreign currency exchange contracts 7 7 7 49 — 56 $ 235 $ 49 $ — $ 284 1 The Level 1 private equity investments amount relates to the portion of our SBIC investments that are now publicly traded. (In millions) December 31, 2016 Level 1 Level 2 Level 3 Total ASSETS Investment securities: Available-for-sale: U.S. Treasury, agencies and corporations $ — $ 12,009 $ — $ 12,009 Municipal securities 1,154 1,154 Other debt securities 24 24 Money market mutual funds and other 184 1 185 184 13,188 — 13,372 Trading account 115 115 Other noninterest-bearing investments: Bank-owned life insurance 497 497 Private equity investments 1 18 73 91 Other assets: Agriculture loan servicing and interest-only strips 20 20 Deferred compensation plan assets 91 91 Derivatives: Interest rate swaps and forwards 4 4 Interest rate swaps for customers 49 49 Foreign currency exchange contracts 11 11 11 53 — 64 $ 304 $ 13,853 $ 93 $ 14,250 LIABILITIES Securities sold, not yet purchased $ 25 $ — $ — $ 25 Other liabilities: Deferred compensation plan obligations 91 91 Derivatives: Interest rate swaps and forwards 1 1 Interest rate swaps for customers 49 49 Foreign currency exchange contracts 9 9 9 50 — 59 $ 125 $ 50 $ — $ 175 1 The Level 1 private equity investments amount relates to the portion of our SBIC investments that are now publicly traded. 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 (In millions) Private equity investments Ag loan svcg and int-only strips Balance at December 31, 2016 $ 73 $ 20 Net gains included in: Statement of income: Securities gains, net 3 Purchases 7 Redemptions and paydowns (5 ) Balance at March 31, 2017 $ 78 $ 20 Level 3 Instruments Three Months Ended (In millions) Private equity investments Ag loan svcg and int-only strips Balance at December 31, 2015 $ 58 $ 14 Net gains included in: Statement of income: Securities gains, net 1 Other noninterest income 3 Purchases 2 Balance at March 31, 2016 $ 61 $ 17 No transfers of assets or liabilities occurred among Levels 1, 2 or 3 for the three months ended March 31, 2017 and 2016 . The preceding reconciling amounts using Level 3 inputs include the following realized gains in the statement of income: (In millions) Three Months Ended 2017 2016 Securities gains, net $ 3 $ — 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, 2017 Fair value at December 31, 2016 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total ASSETS Private equity investments $ — $ — $ 1 $ 1 $ — $ — $ 1 $ 1 Impaired loans — 1 — 1 — 52 — 52 Other real estate owned — — — — — 1 — 1 $ — $ 1 $ 1 $ 2 $ — $ 53 $ 1 $ 54 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 2017 2016 ASSETS Private equity investments $ (1 ) $ — Impaired loans (1 ) (15 ) $ (2 ) $ (15 ) During the three months ended March 31, we recognized an insignificant amount of net gains in 2017 and $2 million in 2016 from the sale of other real estate owned (“OREO”) properties that had a carrying value at the time of sale of approximately $2 million for each period. Previous to their sale in these periods, we recognized impairment on these properties of an insignificant amount in 2017 and 2016 . 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 $12 million at March 31, 2017 and $13 million at December 31, 2016 . Amounts of other noninterest-bearing investments carried at cost were $293 million at March 31, 2017 and $211 million at December 31, 2016 , which were comprised of Federal Reserve and FHLB stock. Private equity investments accounted for using the equity method were $38 million at March 31, 2017 and $35 million at December 31, 2016 . 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. Measurement of fair value for collateral-dependent loans and OREO was based on third party appraisals that utilize one or more valuation techniques (income, market and/or cost approaches). Any adjustments to calculated fair value were made based on recently completed and validated third party appraisals, third party appraisal services, automated valuation services, or our informed judgment. Evaluations were made to determine that the appraisal process met the relevant concepts and requirements of applicable accounting guidance. Automated valuation services may be used primarily for residential properties when values from any of the previous methods were not available within 90 days of the balance sheet date. These services use models based on market, economic, and demographic values. The use of these models has only occurred in a very few instances and the related property valuations have not been sufficiently significant to consider disclosure under Level 3 rather than Level 2. Impaired loans that are not collateral dependent were measured based on the present value of future cash flows discounted at the expected coupon rates over the lives of the loans. Because the loans were not discounted at market interest rates, the valuations do not represent fair value and have been excluded from the nonrecurring fair value balance in the preceding schedules. Fair Value of Certain Financial Instruments Following is a summary of the carrying values and estimated fair values of certain financial instruments: March 31, 2017 December 31, 2016 (In millions) Carrying value Estimated fair value Level Carrying value Estimated fair value Level Financial assets: HTM investment securities $ 815 $ 803 2 $ 868 $ 850 2 Loans and leases (including loans held for sale), net of allowance 42,326 42,038 3 42,254 42,111 3 Financial liabilities: Time deposits 2,994 2,977 2 2,757 2,744 2 Other short-term borrowings 2,500 2,500 2 500 500 2 Long-term debt 383 404 2 535 552 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. Financial instruments for which carrying values approximate fair value include cash and due from banks, money market investments, demand, savings and money market deposits, federal funds purchased and other short-term borrowings, and security repurchase agreements. The estimated fair value of demand, savings and money market deposits is the amount payable on demand at the reporting date. Carrying value is used because the accounts have no stated maturity and the customer has the ability to withdraw funds immediately. HTM investment securities primarily consist of municipal securities. They were measured at fair value according to the methodology previously discussed. Loans are measured at fair value according to their status as nonimpaired or impaired. For nonimpaired loans, fair value is estimated by discounting future cash flows using the LIBOR yield curve adjusted by a factor which reflects the credit and interest rate risk inherent in the loan. These future cash flows are then reduced by the estimated “life-of-the-loan” aggregate credit losses in the loan portfolio. These adjustments for lifetime future credit losses are derived from the methods used to estimate the allowance for loan and lease losses (“ALLL”) for our loan portfolio and are adjusted quarterly as necessary to reflect the most recent loss experience. Impaired loans that are collateral dependent are already considered to be held at fair value. Impaired loans that are not collateral dependent have future cash flows reduced by the estimated “life-of-the-loan” credit loss derived from methods used to estimate the ALLL for these loans. See Impaired Loans in Note 6 for details on the impairment measurement method for impaired loans. Loans, other than those held for sale, are not normally purchased and sold by the Company, and there are no active trading markets for most of this portfolio. Time and foreign deposits, and any other short-term borrowings, are measured at fair value by discounting future cash flows using the LIBOR yield curve to the given maturity dates. Long-term debt is measured at fair value based on actual market trades (i.e., an asset value) when available, or discounting cash flows to maturity using the LIBOR yield curve adjusted for credit spreads. These fair value disclosures represent our best estimates based on relevant market information and information about the financial instruments. Fair value estimates are based on judgments regarding current economic conditions, future expected loss experience, risk characteristics of the various instruments, and other factors. These estimates are subjective in nature, involve uncertainties and matters of significant judgment, and cannot be determined with precision. Changes in these methodologies and assumptions could significantly affect the estimates.

Offsetting Assets and Liabiliti

Offsetting Assets and Liabilities (Notes)	3 Months Ended
	Mar. 31, 2017
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, 2017 (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 $ 757 $ (394 ) $ 363 $ — $ — $ 363 Derivatives (included in other assets) 55 — 55 (17 ) — 38 $ 812 $ (394 ) $ 418 $ (17 ) $ — $ 401 Liabilities: Federal funds and other short-term borrowings $ 3,531 $ (394 ) $ 3,137 $ — $ — $ 3,137 Derivatives (included in other liabilities) 56 — 56 (17 ) (14 ) 25 $ 3,587 $ (394 ) $ 3,193 $ (17 ) $ (14 ) $ 3,162 December 31, 2016 (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 $ 568 $ — $ 568 $ — $ — $ 568 Derivatives (included in other assets) 64 — 64 (17 ) — 47 $ 632 $ — $ 632 $ (17 ) $ — $ 615 Liabilities: Federal funds and other short-term borrowings $ 827 $ — $ 827 $ — $ — $ 827 Derivatives (included in other liabilities) 59 — 59 (17 ) (17 ) 25 $ 886 $ — $ 886 $ (17 ) $ (17 ) $ 852 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 Company’s balance sheet. See Note 7 for further information regarding derivative instruments.

Investment Securities

Investment Securities	3 Months Ended
	Mar. 31, 2017
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 are reported as net increases or decreases to accumulated other comprehensive income (“AOCI”). Trading securities are carried at fair value with gains and losses recognized in current period earnings. The purchase premiums and discounts for both 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 as interest income in the period the principal is reduced. Note 3 discusses the process to estimate fair value for investment securities. March 31, 2017 (In millions) Amortized cost Gross unrealized gains Gross unrealized losses Estimated fair value Held-to-maturity Municipal securities $ 815 $ 7 $ 19 $ 803 Available-for-sale U.S. Government agencies and corporations: Agency securities 1,858 3 8 1,853 Agency guaranteed mortgage-backed securities 10,060 12 111 9,961 SBA loan-backed securities 2,360 8 19 2,349 Municipal securities 1,299 4 18 1,285 Other debt securities 25 — 1 24 15,602 27 157 15,472 Money market mutual funds and other 134 — — 134 15,736 27 157 15,606 Total $ 16,551 $ 34 $ 176 $ 16,409 December 31, 2016 (In millions) Amortized Gross unrealized gains Gross unrealized losses Estimated Held-to-maturity Municipal securities $ 868 $ 5 $ 23 $ 850 Available-for-sale U.S. Government agencies and corporations: Agency securities 1,846 2 9 1,839 Agency guaranteed mortgage-backed securities 7,986 7 110 7,883 SBA loan-backed securities 2,298 8 18 2,288 Municipal securities 1,182 1 29 1,154 Other debt securities 25 — 1 24 13,337 18 167 13,188 Money market mutual funds and other 184 — — 184 13,521 18 167 13,372 Total $ 14,389 $ 23 $ 190 $ 14,222 Maturities The amortized cost and estimated fair value of investment debt securities are shown subsequently as of March 31, 2017 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, 2017 Held-to-maturity Available-for-sale (In millions) Amortized cost Estimated fair value Amortized cost Estimated fair value Principal return in one year or less $ 142 $ 142 $ 1,884 $ 1,868 Principal return after one year through five years 273 274 5,875 5,828 Principal return after five years through ten years 196 196 4,904 4,860 Principal return after ten years 204 191 2,939 2,916 $ 815 $ 803 $ 15,602 $ 15,472 The following is a summary of the amount of gross unrealized losses for investment securities and the estimated fair value by length of time the securities have been in an unrealized loss position: March 31, 2017 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 $ 10 $ 309 $ 9 $ 128 $ 19 $ 437 Available-for-sale U.S. Government agencies and corporations: Agency securities 7 1,297 1 124 8 1,421 Agency guaranteed mortgage-backed securities 103 7,220 8 440 111 7,660 Small Business Administration loan-backed securities 4 547 15 798 19 1,345 Municipal securities 17 811 1 14 18 825 Other — — 1 13 1 13 131 9,875 26 1,389 157 11,264 Total $ 141 $ 10,184 $ 35 $ 1,517 $ 176 $ 11,701 December 31, 2016 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 $ 15 $ 467 $ 8 $ 61 $ 23 $ 528 Available-for-sale U.S. Government agencies and corporations: Agency securities 9 950 — 127 9 1,077 Agency guaranteed mortgage-backed securities 102 6,649 7 326 109 6,975 Small Business Administration loan-backed securities 3 527 16 841 19 1,368 Municipal securities 28 992 — 9 28 1,001 Other — — 2 14 2 14 142 9,118 25 1,317 167 10,435 Total $ 157 $ 9,585 $ 33 $ 1,378 $ 190 $ 10,963 At March 31, 2017 and December 31, 2016 , respectively, 453 and 642 HTM and 2,121 and 2,398 AFS investment securities were in an unrealized loss position. Other-Than-Temporary Impairment Ongoing Policy We review investment securities on a quarterly basis for the presence of other-than-temporary impairment (“OTTI”). We assess whether OTTI is present when the fair value of a debt security is less than its amortized cost basis at the balance sheet date (the majority of the investment portfolio are debt securities). Under these circumstances, OTTI is considered to have occurred if (1) we have formed a documented intent to sell identified securities or initiated such sales; (2) it is “more likely than not” we will be required to sell the security before recovery of its amortized cost basis; or (3) the present value of expected cash flows is not sufficient to recover the entire amortized cost basis. Noncredit-related OTTI in securities we intend to sell is recognized in earnings as is any credit-related OTTI in securities, regardless of our intent. Noncredit-related OTTI on AFS securities not expected to be sold is recognized in other comprehensive income (“OCI”). The amount of noncredit-related OTTI in a security is quantified as the difference in a security’s amortized cost after adjustment for credit impairment, and its lower fair value. Presentation of OTTI is made in the statement of income on a gross basis with an offset for the amount of OTTI recognized in OCI. Our OTTI evaluation process takes into consideration current market conditions; fair value in relationship to cost; extent and nature of change in fair value; severity and duration of the impairment; recent events specific to the issuer or industry; our assessment of the creditworthiness of the issuer, including external credit ratings, changes, recent downgrades, and trends; the cash flow priority position of the instrument that we hold in the case of structured securities; volatility of earnings and trends; current analysts’ evaluations; all available information relevant to the collectability of debt securities; and other key measures. In addition, for AFS securities with fair values below amortized cost, we must determine if we intend to sell the securities or if it is more likely than not that we will be required to sell the securities before recovery of their amortized cost basis. For HTM securities, we must determine we have the ability to hold the securities to maturity. We consider any other relevant factors before concluding our evaluation for the existence of OTTI in our securities portfolio. OTTI Conclusions Our 2016 Annual Report on Form 10-K describes in more detail our OTTI evaluation process. The following summarizes the conclusions from our OTTI evaluation by each security type that has significant gross unrealized losses at March 31, 2017 : Agency Guaranteed Mortgage-Backed Securities: These pass-through securities are comprised largely of fixed and floating-rate residential mortgage-backed securities issued by the Government National Mortgage Association (“GNMA”), the Federal National Mortgage Association, or the Federal Home Loan Mortgage Corporation. They were generally purchased at premiums with maturity dates from 10 to 15 years for fixed-rate securities and 30 years for floating-rate securities. These securities benefit from certain guarantee provisions or, in the case of GNMA, direct U.S. government guarantees. Unrealized losses relate to changes in interest rates subsequent to purchase and are not attributable to credit. At March 31, 2017 , 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. Therefore, these securities did not have any OTTI recognized during the first quarter of 2017 . SBA Loan-Backed Securities: These securities were generally purchased at premiums with maturities from 5 to 25 years and have principal cash flows guaranteed by the SBA. Unrealized losses relate to changes in interest rates subsequent to purchase and are not attributable to credit. At March 31, 2017 , we did not have an intent to sell identified SBA securities with unrealized losses or initiate such sales, and we believe it is not likely that we would be required to sell such securities before recovery of their amortized cost basis. Therefore, these securities did not have any OTTI recognized during the first quarter of 2017 . Municipal Securities: These securities were fixed or variable-rate securities purchased at premiums or at par and with maturities from 1 to 30 years. Unrealized losses may relate to changes in interest rates subsequent to purchase and/or may be attributable to credit. Securities with significant credit deterioration and fair value declines are subject to further assessment for impairment including analysis of the creditworthiness of the issuer. We take into account all available information relevant to the collectability of municipal security, including the extent and nature of change in fair value; recent events specific to the issuer; current analysts’ evaluations; and other key measures. At March 31, 2017 , 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. Therefore, these securities did not have any OTTI recognized during the first quarter of 2017 . The following summarizes gains and losses, including OTTI, of which there was none, that were recognized in the statement of income: Three Months Ended March 31, 2017 March 31, 2016 (In millions) Gross gains Gross losses Gross gains Gross losses Investment securities: Held-to-maturity $ — $ — $ — $ — Available-for-sale — — — — Other noninterest-bearing investments 10 5 3 3 10 5 3 3 Net gains $ 5 $ — Statement of income information: Securities gains, net $ 5 $ — Net gains $ 5 $ — Interest income by security type is as follows: (In millions) Three Months Ended Three Months Ended Taxable Nontaxable Total Taxable Nontaxable Total Investment securities: Held-to-maturity $ 3 $ 4 $ 7 $ 2 $ 3 $ 5 Available-for-sale 66 5 71 40 2 42 $ 69 $ 9 $ 78 $ 42 $ 5 $ 47 Investment securities with a carrying value of $2.1 billion at March 31, 2017 and $1.4 billion at December 31, 2016 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. Private Equity Investments Effect of Volcker Rule The Volcker Rule, as published pursuant to the Dodd-Frank Act in December 2013 and amended in January 2014, significantly restricted certain activities by covered bank holding companies, including restrictions on certain types of securities, proprietary trading, and private equity investing. The Company’s private equity investments (“PEIs”) consist of Small Business Investment Companies (“SBICs”) and non-SBICs. Of the recorded PEIs of $143 million at March 31, 2017 , approximately $5 million remain prohibited by the Volcker Rule. As of March 31, 2017 , we have sold a total of $11 million of PEIs during 2017 and 2016 as follows: $1 million during 2017 and $10 million during 2016 . All of these sales were related to prohibited PEIs and resulted in insignificant amounts of realized gains or losses. We will dispose of the remaining $5 million of prohibited PEIs before the required deadline, which has been extended to July 21, 2017. The Federal Reserve Board announced in December 2016 that it would allow banks to apply for an additional five-year extension to comply with the Dodd-Frank Act requirement for these investments. The Company applied for and was granted an extension for the vast majority of its remaining portfolio of PEIs. See other discussions related to private equity investments in Notes 3 and 9 . As discussed in Note 9 , we have $24 million at March 31, 2017 of unfunded commitments for PEIs, of which approximately $3 million relate to prohibited PEIs. Until we dispose of the prohibited PEIs, we expect to fund these commitments if and as the capital calls are made, as allowed under the Volcker Rule.

Loans And Allowance For Credit

Loans And Allowance For Credit Losses	3 Months Ended
	Mar. 31, 2017
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 $ 128 $ 172 Commercial: Commercial and industrial $ 13,368 $ 13,452 Leasing 404 423 Owner-occupied 6,973 6,962 Municipal 811 778 Total commercial 21,556 21,615 Commercial real estate: Construction and land development 2,123 2,019 Term 9,083 9,322 Total commercial real estate 11,206 11,341 Consumer: Home equity credit line 2,638 2,645 1-4 family residential 6,185 5,891 Construction and other consumer real estate 517 486 Bankcard and other revolving plans 459 481 Other 181 190 Total consumer 9,980 9,693 Total loans $ 42,742 $ 42,649 Loan balances are presented net of unearned income and fees, which amounted to $69 million at March 31, 2017 and $77 million at December 31, 2016 . Owner-occupied and commercial real estate (“CRE”) loans include unamortized premiums of approximately $18 million at March 31, 2017 and $20 million at December 31, 2016 . Municipal loans generally include loans to 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 development loans included in the construction and land development loan class were $283 million at March 31, 2017 and $290 million at December 31, 2016 . Loans with a carrying value of approximately $22.2 billion at March 31, 2017 and $24.0 billion at December 31, 2016 have been pledged at the Federal Reserve and the FHLB of Des Moines as collateral for current and potential borrowings. We sold loans totaling $316 million and $273 million for the three months ended March 31, 2017 and 2016 , 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 SBA loans. The loans are mainly sold to U.S. government agencies or participated to third parties. We generally have continuing involvement with the transferred loans, typically in the form of servicing rights or securities that are backed by the transferred loans in addition to a guarantee from the respective agency. The securities we receive in a loan transfer are not restricted from being pledged or exchanged. Amounts added to loans held for sale during these same periods were $303 million and $236 million , respectively. The principal balance of sold loans for which we retain servicing was approximately $2.0 billion at both March 31, 2017 and December 31, 2016 . Income from loans sold, excluding servicing, was $4 million and $3 million for the three months ended March 31, 2017 and 2016 , respectively. Allowance for Credit Losses The ACL consists of the ALLL and the reserve for unfunded lending commitments (“RULC”). Allowance for Loan and Lease Losses The ALLL represents our estimate of probable and estimable losses inherent in the loan and lease portfolio as of the balance sheet date. Losses are charged to the ALLL when recognized. Generally, commercial and CRE loans are charged off or charged down when they are determined to be uncollectible in whole or in part, or when 180 days past due unless the loan is well secured and in process of collection. Consumer loans are either charged off or charged down to net realizable value no later than the month in which they become 180 days past due. Closed-end consumer loans that are not secured by residential real estate are either charged off or charged down to net realizable value no later than the month in which they become 120 days past due. We establish the amount of the ALLL by analyzing the portfolio at least quarterly, and we adjust the provision for loan losses so the ALLL is at an appropriate level at the balance sheet date. We determine our ALLL as the best estimate within a range of estimated losses. The methodologies we use to estimate the ALLL depend upon the impairment status and loan portfolio. The methodology for impaired loans is discussed subsequently. For commercial and CRE loans with commitments equal to or greater than $750,000 , we assign internal risk grades using a comprehensive loan grading system based on financial and statistical models, individual credit analysis, and loan officer experience and judgment. The credit quality indicators discussed subsequently are based on this grading system. Estimated losses for these commercial and CRE loans are derived from a statistical analysis of our historical default and loss given default experience over the period of January 2008 through the most recent full quarter. For consumer and small commercial and CRE loans with commitments less than $750,000 , we primarily use roll rate models to forecast probable inherent losses. Roll rate models measure the rate at which these loans migrate from one delinquency category to the next worse delinquency category, and eventually to loss. We estimate roll rates for these loans using recent delinquency and loss experience by segmenting our loan portfolios into separate pools based on common risk characteristics and separately calculating historical delinquency and loss experience for each pool. These roll rates are then applied to current delinquency levels to estimate probable inherent losses. The current status and historical changes in qualitative and environmental factors may not be reflected in our quantitative models. Thus, after applying historical loss experience, as described above, we review the quantitatively derived level of ALLL for each segment using qualitative criteria and use those criteria to determine our estimate within the range. We track various risk factors that influence our judgment regarding the level of the ALLL across the portfolio segments. These factors primarily include: • Changes in lending policies and procedures, including changes in underwriting standards and collection, charge-off, and recovery practices • Changes in international, national, regional, and local economic and business conditions • Changes in the nature and volume of the portfolio and in the terms of loans • Changes in the experience, ability, and depth of lending management and other relevant staff • Changes in the volume and severity of past due loans, the volume of nonaccrual loans, and the volume and severity of adversely classified or graded loans • Changes in the quality of the loan review system • Changes in the value of underlying collateral for collateral-dependent loans • The existence and effect of any concentration of credit, and changes in the level of such concentrations • The effect of other external factors such as competition and legal and regulatory requirements The magnitude of the impact of these factors on our qualitative assessment of the ALLL changes from quarter to quarter according to changes made by management in its assessment of these factors, the extent these factors are already reflected in historic loss rates, and the extent changes in these factors diverge from one to another. We also consider the uncertainty inherent in the estimation process when evaluating the ALLL. Reserve for Unfunded Lending Commitments 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. The loss factors used in the RULC are the same as the loss factors used in the ALLL, and the qualitative adjustments used in the RULC are the same as the qualitative adjustments used in the ALLL. We adjust the Company’s unfunded lending commitments that are not unconditionally cancelable to an outstanding amount equivalent using credit conversion factors, and we apply the loss factors to the outstanding equivalents. Changes in the allowance for credit losses are summarized as follows: Three Months Ended March 31, 2017 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses Balance at beginning of period $ 420 $ 116 $ 31 $ 567 Additions: Provision for loan losses 22 (3 ) 4 23 Deductions: Gross loan and lease charge-offs (51 ) (1 ) (5 ) (57 ) Recoveries 6 2 3 11 Net loan and lease (charge-offs) recoveries (45 ) 1 (2 ) (46 ) Balance at end of period $ 397 $ 114 $ 33 $ 544 Reserve for unfunded lending commitments Balance at beginning of period $ 54 $ 11 $ — $ 65 Provision credited to earnings (4 ) (1 ) — (5 ) Balance at end of period $ 50 $ 10 $ — $ 60 Total allowance for credit losses at end of period Allowance for loan losses $ 397 $ 114 $ 33 $ 544 Reserve for unfunded lending commitments 50 10 — 60 Total allowance for credit losses $ 447 $ 124 $ 33 $ 604 Three Months Ended March 31, 2016 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses Balance at beginning of period $ 454 $ 114 $ 38 $ 606 Additions: Provision for loan losses 46 2 (6 ) 42 Deductions: Gross loan and lease charge-offs (43 ) (1 ) (4 ) (48 ) Recoveries 7 3 2 12 Net loan and lease (charge-offs) recoveries (36 ) 2 (2 ) (36 ) Balance at end of period $ 464 $ 118 $ 30 $ 612 Reserve for unfunded lending commitments Balance at beginning of period $ 58 $ 17 $ — $ 75 Provision credited to earnings (2 ) (4 ) — (6 ) Balance at end of period $ 56 $ 13 $ — $ 69 Total allowance for credit losses at end of period Allowance for loan losses $ 464 $ 118 $ 30 $ 612 Reserve for unfunded lending commitments 56 13 — 69 Total allowance for credit losses $ 520 $ 131 $ 30 $ 681 The ALLL and outstanding loan balances according to the Company’s impairment method are summarized as follows: March 31, 2017 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses: Individually evaluated for impairment $ 43 $ 3 $ 5 $ 51 Collectively evaluated for impairment 354 111 27 492 Purchased loans with evidence of credit deterioration — — 1 1 Total $ 397 $ 114 $ 33 $ 544 Outstanding loan balances: Individually evaluated for impairment $ 490 $ 82 $ 73 $ 645 Collectively evaluated for impairment 21,033 11,093 9,900 42,026 Purchased loans with evidence of credit deterioration 33 31 7 71 Total $ 21,556 $ 11,206 $ 9,980 $ 42,742 December 31, 2016 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses: Individually evaluated for impairment $ 56 $ 3 $ 6 $ 65 Collectively evaluated for impairment 364 113 25 502 Purchased loans with evidence of credit deterioration — — — — Total $ 420 $ 116 $ 31 $ 567 Outstanding loan balances: Individually evaluated for impairment $ 466 $ 78 $ 75 $ 619 Collectively evaluated for impairment 21,111 11,231 9,611 41,953 Purchased loans with evidence of credit deterioration 38 32 7 77 Total $ 21,615 $ 11,341 $ 9,693 $ 42,649 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. Factors we consider in determining whether a loan is placed on nonaccrual include delinquency status, collateral value, borrower or guarantor financial statement information, bankruptcy status, and other information which would indicate that the full and timely collection of interest and principal is uncertain. A nonaccrual loan may be returned to accrual status when all delinquent interest and principal become current in accordance with the terms of the loan agreement; the loan, if secured, is well secured; the borrower has paid according to the contractual terms for a minimum of six months; and analysis of the borrower indicates a reasonable assurance of the ability and willingness to maintain payments. Payments received on nonaccrual loans are applied as a reduction to the principal outstanding. Closed-end loans with payments scheduled monthly are reported as past due when the borrower is in arrears for two or more monthly payments. Similarly, open-end credit such as charge-card plans and other revolving credit plans are reported as past due when the minimum payment has not been made for two or more billing cycles. Other multi-payment obligations (i.e., quarterly, semiannual, etc.), single payment, and demand notes are reported as past due when either principal or interest is due and unpaid for a period of 30 days or more. Nonaccrual loans are summarized as follows: (In millions) March 31, December 31, Loans held for sale $ 34 $ 40 Commercial: Commercial and industrial $ 358 $ 354 Leasing 13 14 Owner-occupied 89 74 Municipal 1 1 Total commercial 461 443 Commercial real estate: Construction and land development 7 7 Term 38 29 Total commercial real estate 45 36 Consumer: Home equity credit line 9 11 1-4 family residential 35 36 Construction and other consumer real estate 1 2 Bankcard and other revolving plans — 1 Total consumer loans 45 50 Total $ 551 $ 529 Past due loans (accruing and nonaccruing) are summarized as follows: March 31, 2017 (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 $ 113 $ 15 $ — $ 15 $ 128 $ — $ 19 Commercial: Commercial and industrial $ 13,176 $ 94 $ 98 $ 192 $ 13,368 $ 9 $ 245 Leasing 401 2 1 3 404 — 11 Owner-occupied 6,880 59 34 93 6,973 3 35 Municipal 811 — — — 811 — 1 Total commercial 21,268 155 133 288 21,556 12 292 Commercial real estate: Construction and land development 2,113 3 7 10 2,123 — — Term 9,047 11 25 36 9,083 14 24 Total commercial real estate 11,160 14 32 46 11,206 14 24 Consumer: Home equity credit line 2,626 7 5 12 2,638 2 4 1-4 family residential 6,156 11 18 29 6,185 — 11 Construction and other consumer real estate 509 6 2 8 517 1 — Bankcard and other revolving plans 454 3 2 5 459 1 — Other 180 1 — 1 181 — — Total consumer loans 9,925 28 27 55 9,980 4 15 Total $ 42,353 $ 197 $ 192 $ 389 $ 42,742 $ 30 $ 331 December 31, 2016 (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 $ 172 $ — $ — $ — $ 172 $ — $ 40 Commercial: Commercial and industrial $ 13,306 $ 72 $ 74 $ 146 $ 13,452 $ 10 $ 287 Leasing 423 — — — 423 — 14 Owner-occupied 6,894 40 28 68 6,962 8 43 Municipal 778 — — — 778 — 1 Total commercial 21,401 112 102 214 21,615 18 345 Commercial real estate: Construction and land development 2,010 7 2 9 2,019 1 1 Term 9,291 9 22 31 9,322 12 18 Total commercial real estate 11,301 16 24 40 11,341 13 19 Consumer: Home equity credit line 2,635 4 6 10 2,645 1 5 1-4 family residential 5,857 12 22 34 5,891 — 11 Construction and other consumer real estate 479 3 4 7 486 3 — Bankcard and other revolving plans 478 2 1 3 481 1 1 Other 189 1 — 1 190 — — Total consumer loans 9,638 22 33 55 9,693 5 17 Total $ 42,340 $ 150 $ 159 $ 309 $ 42,649 $ 36 $ 381 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, Substandard, and Doubtful, which are consistent with published definitions of regulatory risk classifications. Definitions of Pass, Special Mention, Substandard, and Doubtful are summarized as follows: Pass – A Pass asset is higher quality and does not fit any of the other categories described below. The likelihood of loss is considered low. Special Mention – A Special Mention asset has potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the asset or in the Bank’s credit position at some future date. Substandard – A Substandard asset is inadequately protected by the current sound worth and paying capacity of the obligor or of the collateral pledged, if any. Assets so classified have well-defined weaknesses and are characterized by the distinct possibility that the Bank may sustain some loss if deficiencies are not corrected. Doubtful – A Doubtful asset has all the weaknesses inherent in a Substandard asset with the added characteristics that the weaknesses make collection or liquidation in full highly questionable and improbable. We generally assign internal risk grades to commercial and CRE loans with commitments equal to or greater than $750,000 based on financial and statistical models, individual credit analysis, and loan officer experience and judgment. For these larger loans, we assign one of multiple grades within the Pass classification or one of the following four grades: Special Mention, Substandard, Doubtful, and Loss. Loss indicates that the outstanding balance has been charged off. We confirm our internal risk grades quarterly, or as soon as we identify information that affects the credit risk of the loan. For consumer loans and certain small commercial and CRE loans with commitments less than $750,000 , we generally assign internal risk grades similar to those described previously based on automated rules that depend on refreshed credit scores, payment performance, and other risk indicators. These are generally assigned either a Pass or Substandard grade and are reviewed as we identify information that might warrant a grade change. Outstanding loan balances (accruing and nonaccruing) categorized by these credit quality indicators are summarized as follows: March 31, 2017 (In millions) Pass Special Mention Sub- standard Doubtful Total loans Total allowance Commercial: Commercial and industrial $ 12,175 $ 305 $ 887 $ 1 $ 13,368 Leasing 376 5 23 — 404 Owner-occupied 6,573 104 296 — 6,973 Municipal 805 — 6 — 811 Total commercial 19,929 414 1,212 1 21,556 $ 397 Commercial real estate: Construction and land development 2,043 23 57 — 2,123 Term 8,843 111 129 — 9,083 Total commercial real estate 10,886 134 186 — 11,206 114 Consumer: Home equity credit line 2,620 — 18 — 2,638 1-4 family residential 6,143 — 42 — 6,185 Construction and other consumer real estate 515 — 2 — 517 Bankcard and other revolving plans 457 — 2 — 459 Other 180 — 1 — 181 Total consumer loans 9,915 — 65 — 9,980 33 Total $ 40,730 $ 548 $ 1,463 $ 1 $ 42,742 $ 544 December 31, 2016 (In millions) Pass Special Mention Sub- standard Doubtful Total loans Total allowance Commercial: Commercial and industrial $ 12,185 $ 266 $ 998 $ 3 $ 13,452 Leasing 387 5 30 1 423 Owner-occupied 6,560 96 306 — 6,962 Municipal 765 7 6 — 778 Total commercial 19,897 374 1,340 4 21,615 $ 420 Commercial real estate: Construction and land development 1,942 52 25 — 2,019 Term 9,096 82 144 — 9,322 Total commercial real estate 11,038 134 169 — 11,341 116 Consumer: Home equity credit line 2,629 — 16 — 2,645 1-4 family residential 5,851 — 40 — 5,891 Construction and other consumer real estate 482 — 4 — 486 Bankcard and other revolving plans 478 — 3 — 481 Other 189 — 1 — 190 Total consumer loans 9,629 — 64 — 9,693 31 Total $ 40,564 $ 508 $ 1,573 $ 4 $ 42,649 $ 567 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. For our non-purchased credit-impaired loans, if a nonaccrual loan has a balance greater than $1 million , or if a loan is a troubled debt restructuring (“TDR”), including TDRs that subsequently default, or if the loan is no longer reported as a TDR, we individually evaluate the loan for impairment and estimate a specific reserve for the loan for all portfolio segments under applicable accounting guidance. Smaller nonaccrual loans are pooled for ALLL estimation purposes. Purchase credit-impaired (“PCI”) loans are included in impaired loans and are accounted for under separate accounting guidance. See subsequent discussion under Purchased Loans. When a loan is impaired, we estimate a specific reserve for the loan based on the projected present value of the loan’s future cash flows discounted at the loan’s effective interest rate, the observable market price of the loan, or the fair value of the loan’s underlying collateral. The process of estimating future cash flows also incorporates the same determining factors discussed previously under nonaccrual loans. When we base the impairment amount on the fair value of the loan’s underlying collateral, we generally charge off the portion of the balance that is impaired, such that these loans do not have a specific reserve in the ALLL. 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, 2017 and 2016 was not significant. 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, 2017 and 2016 : March 31, 2017 (In millions) Unpaid principal balance Recorded investment Total recorded investment Related allowance with no allowance with allowance Commercial: Commercial and industrial $ 460 $ 122 $ 285 $ 407 $ 40 Owner-occupied 126 55 57 112 3 Municipal 1 1 — 1 — Total commercial 587 178 342 520 43 Commercial real estate: Construction and land development 20 2 10 12 — Term 98 52 25 77 2 Total commercial real estate 118 54 35 89 2 Consumer: Home equity credit line 23 15 6 21 — 1-4 family residential 57 27 27 54 5 Construction and other consumer real estate 3 2 1 3 — Other 2 1 — 1 — Total consumer loans 85 45 34 79 5 Total $ 790 $ 277 $ 411 $ 688 $ 50 December 31, 2016 (In millions) Unpaid principal balance Recorded investment Total recorded investment Related allowance with no allowance with allowance Commercial: Commercial and industrial $ 470 $ 82 $ 311 $ 393 $ 52 Owner-occupied 115 71 30 101 3 Municipal 1 1 — 1 — Total commercial 586 154 341 495 55 Commercial real estate: Construction and land development 22 7 6 13 — Term 92 53 17 70 2 Total commercial real estate 114 60 23 83 2 Consumer: Home equity credit line 24 16 7 23 — 1-4 family residential 59 27 28 55 6 Construction and other consumer real estate 3 1 2 3 — Other 2 1 — 1 — Total consumer loans 88 45 37 82 6 Total $ 788 $ 259 $ 401 $ 660 $ 63 Three Months Ended Three Months Ended (In millions) Average recorded investment Interest income recognized Average recorded investment Interest income recognized Commercial: Commercial and industrial $ 393 $ 1 $ 282 $ 2 Owner-occupied 101 2 122 2 Municipal 1 — 1 — Total commercial 495 3 405 4 Commercial real estate: Construction and land development 13 — 15 1 Term 68 2 106 3 Total commercial real estate 81 2 121 4 Consumer: Home equity credit line 21 — 25 — 1-4 family residential 54 1 63 1 Construction and other consumer real estate 3 — 3 — Bankcard and other revolving plans — — — — Other 1 — 2 — Total consumer loans 79 1 93 1 Total $ 655 $ 6 $ 619 $ 9 Modified and Restructured Loans Loans may be modified in the normal course of business for competitive reasons or to strengthen the Company’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. These modifications are structured on a loan-by-loan basis and, depending on the circumstances, may include extended payment terms, a modified interest rate, forgiveness of principal, or other concessions. Loans that have been modified to accommodate a borrower who is experiencing financial difficulties, and for which the Company has granted a concession that it would not otherwise consider, are considered TDRs. We consider many factors in determining whether to agree to a loan modification involving concessions, and seek a solution that will both minimize potential loss to the Company and attempt to help the borrower. We evaluate borrowers’ current and forecasted future cash flows, their ability and willingness to make current contractual or proposed modified payments, the value of the underlying collateral (if applicable), the possibility of obtaining additional security or guarantees, and the potential costs related to a repossession or foreclosure and the subsequent sale of the collateral. TDRs are classified as either accrual or nonaccrual loans. A loan on nonaccrual and restructured as a TDR will remain on nonaccrual status until the borrower has proven the ability to perform under the modified structure for a minimum of six months, and there is evidence that such payments can and are likely to continue as agreed. Performance prior to the restructuring, or significant events that coincide with the restructuring, are included in assessing whether the borrower can meet the new terms and may result in the loan being returned to accrual at the time of restructuring or after a shorter performance period. If the borrower’s ability to meet the revised payment schedule is uncertain, the loan remains classified as a nonaccrual loan. A TDR loan that specifies an interest rate that at the time of the restructuring is greater than or equal to the rate the bank is willing to accept for a new loan with comparable risk may not be reported as a TDR or an impaired loan in the calendar years subsequent to the restructuring if it is in compliance with its modified terms. 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, 2017 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 $ 1 $ 29 $ — $ — $ — $ 36 $ 66 Owner-occupied 1 — 1 — 8 11 21 Total commercial 2 29 1 — 8 47 87 Commercial real estate: Construction and land development — 3 — — — 2 5 Term 5 — — 1 2 10 18 Total commercial real estate 5 3 — 1 2 12 23 Consumer: Home equity credit line — 2 10 — — 3 15 1-4 family residential 1 1 7 — 2 29 40 Construction and other consumer real estate — 1 — — — 1 2 Total consumer loans 1 4 17 — 2 33 57 Total accruing 8 36 18 1 12 92 167 Nonaccruing Commercial: Commercial and industrial 4 — 14 1 53 19 91 Owner-occupied 1 2 — 1 2 12 18 Municipal — 1 — — — — 1 Total commercial 5 3 14 2 55 31 110 Commercial real estate: Construction and land development — — — — 2 — 2 Term 2 1 — — 2 3 8 Total commercial real estate 2 1 — — 4 3 10 Consumer: Home equity credit line — — 1 — — — 1 1-4 family residential — 1 2 — 1 5 9 Construction and other consumer real estate — — — 1 — — 1 Total consumer loans — 1 3 1 1 5 11 Total nonaccruing 7 5 17 3 60 39 131 Total $ 15 $ 41 $ 35 $ 4 $ 72 $ 131 $ 298 December 31, 2016 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 $ — $ 19 $ — $ — $ — $ 28 $ 47 Owner-occupied 3 — 1 — 8 10 22 Total commercial 3 19 1 — 8 38 69 Commercial real estate: Construction and land development — 4 — — — 4 8 Term 4 — — 1 2 10 17 Total commercial real estate 4 4 — 1 2 14 25 Consumer: Home equity credit line — 1 10 — — 3 14 1-4 family residential 3 1 6 — 2 30 42 Construction and other consumer real estate — — — — — 1 1 Total consumer loans 3 2 16 — 2 34 57 Total accruing 10 25 17 1 12 86 151 Nonaccruing Commercial: Commercial and industrial 1 — — 1 33 25 60 Owner-occupied — 1 — 3 1 12 17 Municipal — 1 — — — — 1 Total commercial 1 2 — 4 34 37 78 Commercial real estate: Construction and land development — — — — 2 — 2 Term 2 1 — — 2 3 8 Total commercial real estate 2 1 — — 4 3 10 Consumer: Home equity credit line — — 1 — — 1 2 1-4 family residential — — 2 — 1 5 8 Construction and other consumer real estate — — — 2 — — 2 Total consumer loans — — 3 2 1 6 12 Total nonaccruing 3 3 3 6 39 46 100 Total $ 13 $ 28 $ 20 $ 7 $ 51 $ 132 $ 251 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 $19 million at March 31, 2017 and $14 million at December 31, 2016 . The total recorded investment of all TDRs in which interest rates were modified below market was $133 million at March 31, 2017 and $128 million at December 31, 2016 . 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, 2017 and 2016 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 $ — $ 14 $ 14 $ — $ 3 $ 3 Owner-occupied — 2 2 4 — 4 Total commercial — 16 16 4 3 7 Commercial real estate: Term — 2 2 — — — Total commercial real estate — 2 2 — — — Total $ — $ 18 $ 18 $ 4 $ 3 $ 7 Note: Total loans modified as TDRs during the 12 months previous to March 31, 2017 and 2016 were $129 million and $180 million , respectively. At March 31, 2017 and December 31, 2016 , the amount of foreclosed residential real estate property held by the Company was approximately $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 $13 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. Credit risks (whether on- or off-balance sheet) may occur when individual borrowers, groups of borrowers, or counterparties have similar economic characteristics, including industries, geographies, collateral types, sponsors, etc., and are similarly affected by changes in economic or other conditions. Credit risk also includes the loss that would be recognized subsequent to the reporting date if counterparties failed to perform as contracted. See Note 7 for a discussion of counterparty risk associated with the Company’s derivative transactions. We perform an ongoing analysis of our loan portfolio to evaluate whether there is any significant exposure to any concentrations of credit risk. Based on this analysis, we believe that the loan portfolio is generally well diversified; however, there are certain significant concentrations in CRE and oil and gas-related lending. Further, we cannot guarantee that we have fully understood or mitigated all risk concentrations or correlated risks. We have adopted and adhere to concentration limits on various types of CRE lending, particularly construction and land development lending, leveraged and enterprise value lending, municipal lending, and oil and gas-related lending. All of these limits are continually monitored and revised as necessary. Purchased Loans

Derivative Instruments And Hedg

Derivative Instruments And Hedging Activities	3 Months Ended
	Mar. 31, 2017
Summary of Derivative Instruments [Abstract]
Derivative Instruments And Hedging Activities	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES Objectives and Accounting 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. We apply hedge accounting to certain derivatives executed for risk management purposes as described in more detail subsequently. However, we do not apply hedge accounting to all of the derivatives involved in our risk management activities. Derivatives not designated as accounting hedges are not speculative and are used to economically manage our exposure to interest rate movements and other identified risks, but do not meet the strict hedge accounting requirements. We record all derivatives on the balance sheet at fair value. Note 3 discusses the process to estimate fair value for derivatives. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative and the resulting accounting designation. Derivatives used to hedge the exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivatives used to hedge the exposure to variability in expected cash flows, or other types of forecasted transactions, are considered cash flow hedges. For derivatives designated as fair value hedges, changes in the fair value of the derivative are recognized in earnings together with changes in the fair value of the related hedged item. The net amount, if any, representing hedge ineffectiveness, is reflected in earnings. In previous years, we used fair value hedges to manage interest rate exposure to certain long-term debt. These hedges have been terminated and their remaining balances were completely amortized into earnings during 2015. For derivatives designated as cash flow hedges, the effective portion of changes in the fair value of the derivative are recorded in OCI and recognized in earnings when the hedged transaction affects earnings. The ineffective portion of changes in the fair value of cash flow hedges is recognized directly in earnings. We use interest rate swaps as part of our cash flow hedging strategy to hedge the variable cash flows associated with designated commercial loans. These interest rate swap agreements designated as cash flow hedges involve the receipt of fixed-rate amounts in exchange for variable-rate payments over the life of the agreements without exchange of the underlying notional amount. During 2016 we closed our branch in Grand Cayman, Grand Cayman Islands B.W.I. and no longer have foreign operations. No derivatives were designated as hedges of investments in foreign operations during 2016. We assess the effectiveness of each hedging relationship by comparing the changes in fair value or cash flows on the derivative hedging instrument with the changes in fair value or cash flows on the designated hedged item or transaction. For derivatives not designated as accounting hedges, changes in fair value are recognized in earnings. The remaining balances of any derivative instruments terminated prior to maturity, including amounts in AOCI for swap hedges, are accreted or amortized to interest income or expense over the period to their previously stated maturity dates. Amounts in AOCI are reclassified to interest income as interest is earned on related variable-rate loans and as amounts for terminated hedges are accreted or amortized to earnings. For the 12 months following March 31, 2017 , we estimate that no significant amo unt will be reclassified. Collateral and Credit Risk Exposure to credit risk arises from the possibility of nonperformance by counterparties. Financial institutions which are well-capitalized and well-established are the counterparties for those derivatives entered into for asset-liability management and to offset derivatives sold to our customers. The Company reduces its counterparty exposure for derivative contracts by centrally clearing all eligible derivatives. For those derivatives that are not centrally cleared, the counterparties are typically financial institutions or customers of the Company. For those that are financial institutions, we manage our credit exposure through the use of a Credit Support Annex (“CSA”) to International Swaps and Derivative Association master agreements. Eligible collateral types are documented by the CSA and controlled under the Company’s general credit policies. Collateral balances are typically monitored on a daily basis. A valuation haircut policy reflects the fact that collateral may fall in value between the date the collateral is called and the date of liquidation or enforcement. In practice, all of the Company’s collateral held as credit risk mitigation under a CSA is cash. We offer interest rate swaps to our customers to assist them in managing their exposure to changing interest rates. Upon issuance, all of these customer swaps are immediately offset through matching derivative contracts, such that the Company minimizes its interest rate risk exposure resulting from such transactions. Most of these customers do not have the capability for centralized clearing. Therefore, we manage the credit risk through loan underwriting, which includes a credit risk exposure formula for the swap, the same collateral and guarantee protection applicable to the loan and credit approvals, limits, and monitoring procedures. Fee income from customer swaps is included in other service charges, commissions and fees. No significant losses on derivative instruments have occurred as a result of counterparty nonperformance. Nevertheless, the related credit risk is considered and measured when and where appropriate. See Note 6 for further discussion of our underwriting, collateral requirements, and other procedures used to address credit risk. 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 under their contracts. At March 31, 2017 , the fair value of our derivative liabilities was $56 million , for which we were required to pledge cash collateral of approximately $37 million in the normal course of business. If our credit rating were downgraded one notch by either Standard & Poor’s or Moody’s at March 31, 2017 , the additional amount of collateral we could be required to pledge is approximately $1 million . As a result of the 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, 2017 and December 31, 2016 , and the related gain (loss) of derivative instruments for the three months ended March 31, 2017 and 2016 is summarized as follows: March 31, 2017 December 31, 2016 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: Interest rate swaps $ 1,388 $ 1 $ 3 $ 1,388 $ 2 $ 1 Derivatives not designated as hedging instruments Interest rate swaps and forwards 201 1 1 235 2 — Interest rate swaps for customers 1 4,106 44 45 4,162 49 49 Foreign exchange 438 9 7 424 11 9 Total derivatives not designated as hedging instruments 4,745 54 53 4,821 62 58 Total derivatives $ 6,133 $ 55 $ 56 $ 6,209 $ 64 $ 59 1 Notional amounts include both the customer swaps and the offsetting derivative contracts. Three Months Ended March 31, 2017 Three Months Ended March 31, 2016 Amount of derivative gain (loss) recognized/reclassified (In millions) OCI Reclassified from AOCI to interest income 2 Noninterest income (expense) Offset to interest expense OCI Reclassified from AOCI to interest income 2 Noninterest Offset to Derivatives designated as hedging instruments Cash flow hedges 1 : Interest rate swaps $ (2 ) $ 2 $ 21 $ 3 Derivatives not designated as hedging instruments Interest rate swaps and forward contracts $ (1 ) $ — Interest rate swaps for customers 1 — Foreign exchange 4 2 Total derivatives $ (2 ) $ 2 $ 4 $ — $ 21 $ 3 $ 2 $ — Note: These schedules are not intended to present at any given time the Company’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). 2 Amounts for the three months ended March 31 , of $2 million in 2017 and $3 million in 2016 , respectively, are the amounts of reclassification to earnings from AOCI presented in Note 8 . The fair value of derivative assets was reduced by a net credit valuation adjustment of $2 million and $5 million at March 31 , 2017 and 2016 , respectively. The adjustment for derivative liabilities was a $1 million decrease and not significant at March 31 , 2017 and 2016 , respectively. These adjustments are required to reflect both our own nonperformance risk and the respective counterparty’s nonperformance risk.

Debt And Shareholders' Equity

Debt And Shareholders' Equity	3 Months Ended
	Mar. 31, 2017
Capitalization, Long-term Debt and Equity [Abstract]
Debt And Shareholders' Equity	DEBT AND SHAREHOLDERS’ EQUITY Long-term debt is summarized as follows: (In millions) March 31, December 31, 2016 Subordinated notes $ 247 $ 247 Senior notes 135 287 Capital lease obligations 1 1 Total $ 383 $ 535 The preceding carrying values represent the par value of the debt adjusted for any unamortized premium or discount or unamortized debt issuance costs. Debt Redemptions and Maturities During the first three months of 2017 , $153 million of our 4.5% senior notes matured. Shareholders’ Equity During the first quarter of 2017, the Company continued its common stock buyback program and repurchased 1 million shares of common stock outstanding with a fair value of $45 million at an average price of $42.43 per share, leaving $45 million of buyback capacity remaining in the 2016 capital plan (which spans the timeframe of July 2016 to June 2017). On April 27, 2017, we announced that we will redeem all outstanding shares of our 7.9% Series F preferred stock on the redemption date of June 15, 2017, for a cash payment of approximately $144 million . After the redemption date, the Series F preferred shares will cease to be entitled to dividends and the holders of such shares will not be entitled to exercise any right with regard to such shares except that of receiving the redemption amount. The amount of dividends payable with respect to the June 15, 2017 dividend date has been declared and approved, and will amount to $0.49375 per depositary share for a total amount of $3 million . Accumulated Other Comprehensive Income Accumulated other comprehensive income (loss) was $(111) million at March 31, 2017 compared to $(122) million at December 31, 2016 . 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, 2017 Balance at December 31, 2016 $ (93 ) $ 2 $ (31 ) $ (122 ) OCI before reclassifications, net of tax 12 — — 12 Amounts reclassified from AOCI, net of tax — (1 ) — (1 ) OCI (loss) 12 (1 ) — 11 Balance at March 31, 2017 $ (81 ) $ 1 $ (31 ) $ (111 ) Income tax expense (benefit) included in OCI (loss) $ 7 $ (1 ) $ — $ 6 Three Months Ended March 31, 2016 Balance at December 31, 2015 $ (18 ) $ 1 $ (38 ) $ (55 ) OCI before reclassifications, net of tax 32 14 (1 ) 45 Amounts reclassified from AOCI, net of tax — (2 ) — (2 ) OCI (loss) 32 12 (1 ) 43 Balance at March 31, 2016 $ 14 $ 13 $ (39 ) $ (12 ) Income tax expense included in OCI (loss) $ 20 $ 7 $ 1 $ 28 Amounts reclassified from AOCI 1 Statement of income (SI) Balance sheet (BS) (In millions) Three Months Ended Details about AOCI components 2017 2016 Affected line item Net unrealized gains on derivative instruments $ 2 $ 3 SI Interest and fees on loans Income tax expense 1 1 Amounts Reclassified from AOCI $ 1 $ 2 1 Negative reclassification amounts indicate decreases to earnings in the statement of income and increases to balance sheet assets. The opposite applies to positive reclassification amounts.

Commitments, Guarantees, And Co

Commitments, Guarantees, And Contingent Liabilities	3 Months Ended
	Mar. 31, 2017
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 $ 18,467 $ 18,274 Standby letters of credit: Financial 701 771 Performance 191 196 Commercial letters of credit 77 60 Total unfunded lending commitments $ 19,436 $ 19,301 1 Net of participations The Company’s 2016 Annual Report on Form 10-K contains further information about these commitments and guarantees including their terms and collateral requirements. At March 31, 2017 , the Company had recorded approximately $5 million as a liability for the guarantees associated with the standby letters of credit, which consisted of $2 million attributable to the RULC and $3 million of deferred commitment fees. At March 31, 2017 , we had unfunded commitments for PEIs of approximately $24 million . These obligations have no stated maturity. PEIs related to these commitments that are prohibited by the Volcker Rule were $3 million at March 31, 2017 . See related discussions about these investments in Notes 3 and 5 . 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, 2017 , we were subject to the following material litigation and governmental inquiries: • a governmental inquiry conducted by the Department of Justice into our payment processing practices relating to certain telemarketing customers alleged to have engaged in fraudulent marketing practices. The factual issues related to this case are the same as those involved in the Reyes v. Zions First National Bank, et. al. matter which was previously disclosed and settled in December 2016. We commenced substantive settlement discussion with the U.S. Attorney’s Office for the Eastern District of Pennsylvania in the third quarter of 2016. There can be no assurance, however, that the parties will be able to settle this matter. • 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. This case is in an early phase, with initial motion practice having been completed. • 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 by borrower International Manufacturing Group, alleging that International Manufacturing Group, along with its principal, obtained loans and made loan repayments in furtherance of an alleged Ponzi scheme. This case is in an early phase with initial motion practice having been completed. 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, 2017 , we estimated that the aggregate range of reasonably possible losses for those matters to be from $0 million to roughly $20 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.

Retirement Plans

Retirement Plans	3 Months Ended
	Mar. 31, 2017
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Retirement Plans	RETIREMENT PLANS The following discloses the net periodic benefit cost (credit) and its components for the Company’s pension and other retirement plans: Pension and Other Retirement Plans (In millions) Three Months Ended March 31, 2017 2016 Interest cost $ 2 $ 2 Expected return on plan assets (3 ) (3 ) Partial settlement loss 1 — Amortization of net actuarial gain 1 2 Net periodic benefit cost $ 1 $ 1 As disclosed in our 2016 Annual Report on Form 10-K, the Company has frozen its participation and benefit accruals for the pension plan and its contributions for individual benefit payments in the postretirement benefit plan.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The effective income tax rate of 24.5% for the first quarter of 2017 was lower than the 2016 first quarter rate of 31.1% . The tax rates for both the first quarters of 2017 and 2016 were benefited primarily by the non-taxability of certain income items; however, the 2017 effective tax rate was further reduced by other adjustments. In the first quarter of 2017 we re-evaluated our state tax positions which resulted in a one-time $14 million benefit to income tax expense, in addition to a $4 million benefit from the implementation of new accounting guidance related to stock-based compensation. Net deferred tax assets were approximately $231 million at March 31, 2017 and $250 million at December 31, 2016 , which included a $4 million valuation allowance at each respective reporting date for certain acquired net operating loss carryforwards included in our acquisition of the remaining interests in a less significant subsidiary. We evaluate deferred tax assets on a regular basis to determine whether an additional valuation allowance is required. Based on this evaluation, and considering the weight of the positive evidence compared to the negative evidence, we have concluded that an additional valuation allowance is not required as of March 31, 2017 .

Operating Segment Information

Operating Segment Information	3 Months Ended
	Mar. 31, 2017
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 continues to be refined. Total average loans and deposits presented for the banking segments do not include intercompany amounts between banking segments, but may include deposits with the Other segment. Prior period amounts have been reclassified to reflect these changes. As of March 31, 2017 , 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 93 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 the Parent, Zions Management Services Company, 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. Throughout 2016 consolidation efforts continued, which resulted in transitioning full-time equivalents from the business segments to the Company’s back-office units. Due to the continuing nature and timing of this change, the Company’s back-office units retained more direct expenses in 2016 than in prior years. In the first quarter of 2017 we made changes to the FTP process and internal allocation of central expenses to better reflect the performance of business segments. Prior period amounts have been revised to reflect the impact of these changes had they been instituted in 2016. The following schedule does not present total assets or income tax expense for each operating segment, but instead presents average loans, average deposits and net income before income taxes because these are the metrics that management uses when evaluating performance and making decisions pertaining to the operating segments. The Parent’s net interest income includes interest expense on other 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 Company. 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, 2017 and 2016 : (In millions) Zions Bank Amegy CB&T NBAZ NSB 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 SELECTED INCOME STATEMENT DATA Net interest income $ 155 $ 150 $ 114 $ 113 $ 110 $ 103 $ 50 $ 45 $ 32 $ 30 Provision for loan losses 35 (31 ) 1 104 (5 ) (3 ) 1 2 (4 ) (26 ) Net interest income after provision for loan losses 120 181 113 9 115 106 49 43 36 56 Noninterest income 35 36 29 29 17 16 9 10 10 9 Noninterest expense 113 105 85 86 75 72 37 35 35 33 Net Income (loss) before taxes $ 42 $ 112 $ 57 $ (48 ) $ 57 $ 50 $ 21 $ 18 $ 11 $ 32 SELECTED AVERAGE BALANCE SHEET DATA Total loans $ 12,488 $ 12,306 $ 10,637 $ 10,370 $ 9,306 $ 8,905 $ 4,262 $ 3,863 $ 2,338 $ 2,263 Total deposits 16,268 15,700 11,318 11,274 10,921 10,479 4,661 4,445 4,211 4,011 (In millions) Vectra TCBW Other Consolidated Company 2017 2016 2017 2016 2017 2016 2017 2016 SELECTED INCOME STATEMENT DATA Net interest income $ 30 $ 30 $ 11 $ 9 $ (13 ) $ (27 ) $ 489 $ 453 Provision for loan losses (3 ) (3 ) (1 ) (2 ) (1 ) 1 23 42 Net interest income after provision for loan losses 33 33 12 11 (12 ) (28 ) 466 411 Noninterest income 6 6 1 1 25 10 132 117 Noninterest expense 25 23 5 5 39 37 414 396 Net Income (loss) before taxes $ 14 $ 16 $ 8 $ 7 $ (26 ) $ (55 ) $ 184 $ 132 SELECTED AVERAGE BALANCE SHEET DATA Total loans $ 2,535 $ 2,453 $ 877 $ 733 $ 123 $ 110 $ 42,566 $ 41,003 Total deposits 2,791 2,783 1,100 953 942 (90 ) 52,212 49,555

Basis of Presentaion Organizati

Basis of Presentaion Organization and Presentation (Policies)	3 Months Ended
	Mar. 31, 2017
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 (“the Parent”) and its majority-owned subsidiaries (collectively “the Company,” “Zions,” “we,” “our,” “us”) have been prepared in accordance with 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 (“EITF”). In certain cases, ASUs are issued jointly with International Financial Reporting Standards (“IFRS”). Operating results for the three months ended March 31, 2017 and 2016 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, 2016 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 Company’s 2016 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 (“the Parent”) is a financial holding company headquartered in Salt Lake City, Utah, which owns and operates a commercial bank. The Parent and its subsidiaries (collectively “the Company”) provide a full range of banking and related services in 11 Western and Southwestern states through seven separately managed and branded units as follows: Zions Bank, in Utah, Idaho and Wyoming; California Bank & Trust (“CB&T”); Amegy Bank (“Amegy”), in Texas; 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 (“TCBO”) in Oregon. The Parent also owns and operates certain nonbank subsidiaries that engage in financial services.

Fair Value (Tables)

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Schedule Of Assets And Liabilities Measured At Fair Value By Class On A Recurring Basis	(In millions) March 31, 2017 Level 1 Level 2 Level 3 Total ASSETS Investment securities: Available-for-sale: U.S. Treasury, agencies and corporations $ — $ 14,163 $ — $ 14,163 Municipal securities 1,285 1,285 Other debt securities 24 24 Money market mutual funds and other 133 1 134 133 15,473 — 15,606 Trading account 40 40 Other noninterest-bearing investments: Bank-owned life insurance 499 499 Private equity investments 1 15 78 93 Other assets: Agriculture loan servicing and interest-only strips 20 20 Deferred compensation plan assets 95 95 Derivatives: Interest rate swaps and forwards 2 2 Interest rate swaps for customers 44 44 Foreign currency exchange contracts 9 9 9 46 — 55 $ 252 $ 16,058 $ 98 $ 16,408 LIABILITIES Securities sold, not yet purchased $ 133 $ — $ — $ 133 Other liabilities: Deferred compensation plan obligations 95 95 Derivatives: Interest rate swaps and forwards 4 4 Interest rate swaps for customers 45 45 Foreign currency exchange contracts 7 7 7 49 — 56 $ 235 $ 49 $ — $ 284 1 The Level 1 private equity investments amount relates to the portion of our SBIC investments that are now publicly traded. (In millions) December 31, 2016 Level 1 Level 2 Level 3 Total ASSETS Investment securities: Available-for-sale: U.S. Treasury, agencies and corporations $ — $ 12,009 $ — $ 12,009 Municipal securities 1,154 1,154 Other debt securities 24 24 Money market mutual funds and other 184 1 185 184 13,188 — 13,372 Trading account 115 115 Other noninterest-bearing investments: Bank-owned life insurance 497 497 Private equity investments 1 18 73 91 Other assets: Agriculture loan servicing and interest-only strips 20 20 Deferred compensation plan assets 91 91 Derivatives: Interest rate swaps and forwards 4 4 Interest rate swaps for customers 49 49 Foreign currency exchange contracts 11 11 11 53 — 64 $ 304 $ 13,853 $ 93 $ 14,250 LIABILITIES Securities sold, not yet purchased $ 25 $ — $ — $ 25 Other liabilities: Deferred compensation plan obligations 91 91 Derivatives: Interest rate swaps and forwards 1 1 Interest rate swaps for customers 49 49 Foreign currency exchange contracts 9 9 9 50 — 59 $ 125 $ 50 $ — $ 175 1 The Level 1 private equity investments amount relates to the portion of our SBIC investments that are now publicly traded.
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 (In millions) Private equity investments Ag loan svcg and int-only strips Balance at December 31, 2016 $ 73 $ 20 Net gains included in: Statement of income: Securities gains, net 3 Purchases 7 Redemptions and paydowns (5 ) Balance at March 31, 2017 $ 78 $ 20 Level 3 Instruments Three Months Ended (In millions) Private equity investments Ag loan svcg and int-only strips Balance at December 31, 2015 $ 58 $ 14 Net gains included in: Statement of income: Securities gains, net 1 Other noninterest income 3 Purchases 2 Balance at March 31, 2016 $ 61 $ 17
Schedule Of Realized Gains (Losses) Using Level 3 Inputs	(In millions) Three Months Ended 2017 2016 Securities gains, net $ 3 $ —
Schedule Of Assets With Fair Value Changes On Nonrecurring Basis	(In millions) Fair value at March 31, 2017 Fair value at December 31, 2016 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total ASSETS Private equity investments $ — $ — $ 1 $ 1 $ — $ — $ 1 $ 1 Impaired loans — 1 — 1 — 52 — 52 Other real estate owned — — — — — 1 — 1 $ — $ 1 $ 1 $ 2 $ — $ 53 $ 1 $ 54 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 2017 2016 ASSETS Private equity investments $ (1 ) $ — Impaired loans (1 ) (15 ) $ (2 ) $ (15 )
Fair Value, by Balance Sheet Grouping [Table Text Block]	March 31, 2017 December 31, 2016 (In millions) Carrying value Estimated fair value Level Carrying value Estimated fair value Level Financial assets: HTM investment securities $ 815 $ 803 2 $ 868 $ 850 2 Loans and leases (including loans held for sale), net of allowance 42,326 42,038 3 42,254 42,111 3 Financial liabilities: Time deposits 2,994 2,977 2 2,757 2,744 2 Other short-term borrowings 2,500 2,500 2 500 500 2 Long-term debt 383 404 2 535 552 2 March 31, 2017 (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 $ 757 $ (394 ) $ 363 $ — $ — $ 363 Derivatives (included in other assets) 55 — 55 (17 ) — 38 $ 812 $ (394 ) $ 418 $ (17 ) $ — $ 401 Liabilities: Federal funds and other short-term borrowings $ 3,531 $ (394 ) $ 3,137 $ — $ — $ 3,137 Derivatives (included in other liabilities) 56 — 56 (17 ) (14 ) 25 $ 3,587 $ (394 ) $ 3,193 $ (17 ) $ (14 ) $ 3,162 December 31, 2016 (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 $ 568 $ — $ 568 $ — $ — $ 568 Derivatives (included in other assets) 64 — 64 (17 ) — 47 $ 632 $ — $ 632 $ (17 ) $ — $ 615 Liabilities: Federal funds and other short-term borrowings $ 827 $ — $ 827 $ — $ — $ 827 Derivatives (included in other liabilities) 59 — 59 (17 ) (17 ) 25 $ 886 $ — $ 886 $ (17 ) $ (17 ) $ 852

Offsetting Assets and Liabili23

Offsetting Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2017
Offsetting Assets and Liabilities [Abstract]
Fair Value, by Balance Sheet Grouping [Table Text Block]	March 31, 2017 December 31, 2016 (In millions) Carrying value Estimated fair value Level Carrying value Estimated fair value Level Financial assets: HTM investment securities $ 815 $ 803 2 $ 868 $ 850 2 Loans and leases (including loans held for sale), net of allowance 42,326 42,038 3 42,254 42,111 3 Financial liabilities: Time deposits 2,994 2,977 2 2,757 2,744 2 Other short-term borrowings 2,500 2,500 2 500 500 2 Long-term debt 383 404 2 535 552 2 March 31, 2017 (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 $ 757 $ (394 ) $ 363 $ — $ — $ 363 Derivatives (included in other assets) 55 — 55 (17 ) — 38 $ 812 $ (394 ) $ 418 $ (17 ) $ — $ 401 Liabilities: Federal funds and other short-term borrowings $ 3,531 $ (394 ) $ 3,137 $ — $ — $ 3,137 Derivatives (included in other liabilities) 56 — 56 (17 ) (14 ) 25 $ 3,587 $ (394 ) $ 3,193 $ (17 ) $ (14 ) $ 3,162 December 31, 2016 (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 $ 568 $ — $ 568 $ — $ — $ 568 Derivatives (included in other assets) 64 — 64 (17 ) — 47 $ 632 $ — $ 632 $ (17 ) $ — $ 615 Liabilities: Federal funds and other short-term borrowings $ 827 $ — $ 827 $ — $ — $ 827 Derivatives (included in other liabilities) 59 — 59 (17 ) (17 ) 25 $ 886 $ — $ 886 $ (17 ) $ (17 ) $ 852

Investment Securities (Tables)

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Summary Of Investment Securities	March 31, 2017 (In millions) Amortized cost Gross unrealized gains Gross unrealized losses Estimated fair value Held-to-maturity Municipal securities $ 815 $ 7 $ 19 $ 803 Available-for-sale U.S. Government agencies and corporations: Agency securities 1,858 3 8 1,853 Agency guaranteed mortgage-backed securities 10,060 12 111 9,961 SBA loan-backed securities 2,360 8 19 2,349 Municipal securities 1,299 4 18 1,285 Other debt securities 25 — 1 24 15,602 27 157 15,472 Money market mutual funds and other 134 — — 134 15,736 27 157 15,606 Total $ 16,551 $ 34 $ 176 $ 16,409 December 31, 2016 (In millions) Amortized Gross unrealized gains Gross unrealized losses Estimated Held-to-maturity Municipal securities $ 868 $ 5 $ 23 $ 850 Available-for-sale U.S. Government agencies and corporations: Agency securities 1,846 2 9 1,839 Agency guaranteed mortgage-backed securities 7,986 7 110 7,883 SBA loan-backed securities 2,298 8 18 2,288 Municipal securities 1,182 1 29 1,154 Other debt securities 25 — 1 24 13,337 18 167 13,188 Money market mutual funds and other 184 — — 184 13,521 18 167 13,372 Total $ 14,389 $ 23 $ 190 $ 14,222
Contractual Maturities Debt Securities	March 31, 2017 Held-to-maturity Available-for-sale (In millions) Amortized cost Estimated fair value Amortized cost Estimated fair value Principal return in one year or less $ 142 $ 142 $ 1,884 $ 1,868 Principal return after one year through five years 273 274 5,875 5,828 Principal return after five years through ten years 196 196 4,904 4,860 Principal return after ten years 204 191 2,939 2,916 $ 815 $ 803 $ 15,602 $ 15,472
Summary Of Amount Of Gross Unrealized Losses For Debt Securities And Estimated Fair Value	March 31, 2017 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 $ 10 $ 309 $ 9 $ 128 $ 19 $ 437 Available-for-sale U.S. Government agencies and corporations: Agency securities 7 1,297 1 124 8 1,421 Agency guaranteed mortgage-backed securities 103 7,220 8 440 111 7,660 Small Business Administration loan-backed securities 4 547 15 798 19 1,345 Municipal securities 17 811 1 14 18 825 Other — — 1 13 1 13 131 9,875 26 1,389 157 11,264 Total $ 141 $ 10,184 $ 35 $ 1,517 $ 176 $ 11,701	December 31, 2016 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 $ 15 $ 467 $ 8 $ 61 $ 23 $ 528 Available-for-sale U.S. Government agencies and corporations: Agency securities 9 950 — 127 9 1,077 Agency guaranteed mortgage-backed securities 102 6,649 7 326 109 6,975 Small Business Administration loan-backed securities 3 527 16 841 19 1,368 Municipal securities 28 992 — 9 28 1,001 Other — — 2 14 2 14 142 9,118 25 1,317 167 10,435 Total $ 157 $ 9,585 $ 33 $ 1,378 $ 190 $ 10,963
Gains And Losses, Including OTTI, Recognized In Statement Of Income	Three Months Ended March 31, 2017 March 31, 2016 (In millions) Gross gains Gross losses Gross gains Gross losses Investment securities: Held-to-maturity $ — $ — $ — $ — Available-for-sale — — — — Other noninterest-bearing investments 10 5 3 3 10 5 3 3 Net gains $ 5 $ — Statement of income information: Securities gains, net $ 5 $ — Net gains $ 5 $ —
Tax and Nontaxable Interest Income by Investment Type [Table Text Block]	(In millions) Three Months Ended Three Months Ended Taxable Nontaxable Total Taxable Nontaxable Total Investment securities: Held-to-maturity $ 3 $ 4 $ 7 $ 2 $ 3 $ 5 Available-for-sale 66 5 71 40 2 42 $ 69 $ 9 $ 78 $ 42 $ 5 $ 47

Loans And Allowance For Credi25

Loans And Allowance For Credit Losses (Tables)	3 Months Ended
	Mar. 31, 2017
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 $ — $ 14 $ 14 $ — $ 3 $ 3 Owner-occupied — 2 2 4 — 4 Total commercial — 16 16 4 3 7 Commercial real estate: Term — 2 2 — — — Total commercial real estate — 2 2 — — — Total $ — $ 18 $ 18 $ 4 $ 3 $ 7 Note: Total loans modified as TDRs during the 12 months previous to March 31, 2017 and 2016 were $129 million and $180 million , respectively.
Quantitative Information about Transferred Financial Assets that have been Derecognized and Other Financial Assets Managed Together [Table Text Block]	(In billions) March 31, December 31, FN6.6 - Principal balance of loans transferred for which we retain servicing $ 2.0 $ 2.0
allowance for loan losses by impairment [Table Text Block]	The ALLL and outstanding loan balances according to the Company’s impairment method are summarized as follows: March 31, 2017 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses: Individually evaluated for impairment $ 43 $ 3 $ 5 $ 51 Collectively evaluated for impairment 354 111 27 492 Purchased loans with evidence of credit deterioration — — 1 1 Total $ 397 $ 114 $ 33 $ 544 Outstanding loan balances: Individually evaluated for impairment $ 490 $ 82 $ 73 $ 645 Collectively evaluated for impairment 21,033 11,093 9,900 42,026 Purchased loans with evidence of credit deterioration 33 31 7 71 Total $ 21,556 $ 11,206 $ 9,980 $ 42,742 December 31, 2016 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses: Individually evaluated for impairment $ 56 $ 3 $ 6 $ 65 Collectively evaluated for impairment 364 113 25 502 Purchased loans with evidence of credit deterioration — — — — Total $ 420 $ 116 $ 31 $ 567 Outstanding loan balances: Individually evaluated for impairment $ 466 $ 78 $ 75 $ 619 Collectively evaluated for impairment 21,111 11,231 9,611 41,953 Purchased loans with evidence of credit deterioration 38 32 7 77 Total $ 21,615 $ 11,341 $ 9,693 $ 42,649
Summary Of Major Portfolio Segment And Specific Loan Class	(In millions) March 31, December 31, Loans held for sale $ 128 $ 172 Commercial: Commercial and industrial $ 13,368 $ 13,452 Leasing 404 423 Owner-occupied 6,973 6,962 Municipal 811 778 Total commercial 21,556 21,615 Commercial real estate: Construction and land development 2,123 2,019 Term 9,083 9,322 Total commercial real estate 11,206 11,341 Consumer: Home equity credit line 2,638 2,645 1-4 family residential 6,185 5,891 Construction and other consumer real estate 517 486 Bankcard and other revolving plans 459 481 Other 181 190 Total consumer 9,980 9,693 Total loans $ 42,742 $ 42,649
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, 2017 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses Balance at beginning of period $ 420 $ 116 $ 31 $ 567 Additions: Provision for loan losses 22 (3 ) 4 23 Deductions: Gross loan and lease charge-offs (51 ) (1 ) (5 ) (57 ) Recoveries 6 2 3 11 Net loan and lease (charge-offs) recoveries (45 ) 1 (2 ) (46 ) Balance at end of period $ 397 $ 114 $ 33 $ 544 Reserve for unfunded lending commitments Balance at beginning of period $ 54 $ 11 $ — $ 65 Provision credited to earnings (4 ) (1 ) — (5 ) Balance at end of period $ 50 $ 10 $ — $ 60 Total allowance for credit losses at end of period Allowance for loan losses $ 397 $ 114 $ 33 $ 544 Reserve for unfunded lending commitments 50 10 — 60 Total allowance for credit losses $ 447 $ 124 $ 33 $ 604 Three Months Ended March 31, 2016 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses Balance at beginning of period $ 454 $ 114 $ 38 $ 606 Additions: Provision for loan losses 46 2 (6 ) 42 Deductions: Gross loan and lease charge-offs (43 ) (1 ) (4 ) (48 ) Recoveries 7 3 2 12 Net loan and lease (charge-offs) recoveries (36 ) 2 (2 ) (36 ) Balance at end of period $ 464 $ 118 $ 30 $ 612 Reserve for unfunded lending commitments Balance at beginning of period $ 58 $ 17 $ — $ 75 Provision credited to earnings (2 ) (4 ) — (6 ) Balance at end of period $ 56 $ 13 $ — $ 69 Total allowance for credit losses at end of period Allowance for loan losses $ 464 $ 118 $ 30 $ 612 Reserve for unfunded lending commitments 56 13 — 69 Total allowance for credit losses $ 520 $ 131 $ 30 $ 681 The ALLL and outstanding loan balances according to the Company’s impairment method are summarized as follows: March 31, 2017 (In millions) Commercial Commercial real estate Consumer Total Allowance for loan losses: Individually evaluated for impairment $ 43 $ 3 $ 5 $ 51 Collectively evaluated for impairment 354 111 27 492 Purchased loans with evidence of credit deterioration — — 1 1 Total $ 397 $ 114 $ 33 $ 544 Outstanding loan balances: Individually evaluated for impairment $ 490 $ 82 $ 73 $ 645 Collectively evaluated for impairment 21,033 11,093 9,900 42,026 Purchased loans with evidence of credit deterioration 33 31 7 71 Total $ 21,556 $ 11,206 $ 9,980 $ 42,742
Summary Of Nonaccrual Loans	Nonaccrual loans are summarized as follows: (In millions) March 31, December 31, Loans held for sale $ 34 $ 40 Commercial: Commercial and industrial $ 358 $ 354 Leasing 13 14 Owner-occupied 89 74 Municipal 1 1 Total commercial 461 443 Commercial real estate: Construction and land development 7 7 Term 38 29 Total commercial real estate 45 36 Consumer: Home equity credit line 9 11 1-4 family residential 35 36 Construction and other consumer real estate 1 2 Bankcard and other revolving plans — 1 Total consumer loans 45 50 Total $ 551 $ 529
Summary Of Past Due Loans (Accruing And Nonaccruing)	Past due loans (accruing and nonaccruing) are summarized as follows: March 31, 2017 (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 $ 113 $ 15 $ — $ 15 $ 128 $ — $ 19 Commercial: Commercial and industrial $ 13,176 $ 94 $ 98 $ 192 $ 13,368 $ 9 $ 245 Leasing 401 2 1 3 404 — 11 Owner-occupied 6,880 59 34 93 6,973 3 35 Municipal 811 — — — 811 — 1 Total commercial 21,268 155 133 288 21,556 12 292 Commercial real estate: Construction and land development 2,113 3 7 10 2,123 — — Term 9,047 11 25 36 9,083 14 24 Total commercial real estate 11,160 14 32 46 11,206 14 24 Consumer: Home equity credit line 2,626 7 5 12 2,638 2 4 1-4 family residential 6,156 11 18 29 6,185 — 11 Construction and other consumer real estate 509 6 2 8 517 1 — Bankcard and other revolving plans 454 3 2 5 459 1 — Other 180 1 — 1 181 — — Total consumer loans 9,925 28 27 55 9,980 4 15 Total $ 42,353 $ 197 $ 192 $ 389 $ 42,742 $ 30 $ 331 December 31, 2016 (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 $ 172 $ — $ — $ — $ 172 $ — $ 40 Commercial: Commercial and industrial $ 13,306 $ 72 $ 74 $ 146 $ 13,452 $ 10 $ 287 Leasing 423 — — — 423 — 14 Owner-occupied 6,894 40 28 68 6,962 8 43 Municipal 778 — — — 778 — 1 Total commercial 21,401 112 102 214 21,615 18 345 Commercial real estate: Construction and land development 2,010 7 2 9 2,019 1 1 Term 9,291 9 22 31 9,322 12 18 Total commercial real estate 11,301 16 24 40 11,341 13 19 Consumer: Home equity credit line 2,635 4 6 10 2,645 1 5 1-4 family residential 5,857 12 22 34 5,891 — 11 Construction and other consumer real estate 479 3 4 7 486 3 — Bankcard and other revolving plans 478 2 1 3 481 1 1 Other 189 1 — 1 190 — — Total consumer loans 9,638 22 33 55 9,693 5 17 Total $ 42,340 $ 150 $ 159 $ 309 $ 42,649 $ 36 $ 381 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, 2017 (In millions) Pass Special Mention Sub- standard Doubtful Total loans Total allowance Commercial: Commercial and industrial $ 12,175 $ 305 $ 887 $ 1 $ 13,368 Leasing 376 5 23 — 404 Owner-occupied 6,573 104 296 — 6,973 Municipal 805 — 6 — 811 Total commercial 19,929 414 1,212 1 21,556 $ 397 Commercial real estate: Construction and land development 2,043 23 57 — 2,123 Term 8,843 111 129 — 9,083 Total commercial real estate 10,886 134 186 — 11,206 114 Consumer: Home equity credit line 2,620 — 18 — 2,638 1-4 family residential 6,143 — 42 — 6,185 Construction and other consumer real estate 515 — 2 — 517 Bankcard and other revolving plans 457 — 2 — 459 Other 180 — 1 — 181 Total consumer loans 9,915 — 65 — 9,980 33 Total $ 40,730 $ 548 $ 1,463 $ 1 $ 42,742 $ 544 December 31, 2016 (In millions) Pass Special Mention Sub- standard Doubtful Total loans Total allowance Commercial: Commercial and industrial $ 12,185 $ 266 $ 998 $ 3 $ 13,452 Leasing 387 5 30 1 423 Owner-occupied 6,560 96 306 — 6,962 Municipal 765 7 6 — 778 Total commercial 19,897 374 1,340 4 21,615 $ 420 Commercial real estate: Construction and land development 1,942 52 25 — 2,019 Term 9,096 82 144 — 9,322 Total commercial real estate 11,038 134 169 — 11,341 116 Consumer: Home equity credit line 2,629 — 16 — 2,645 1-4 family residential 5,851 — 40 — 5,891 Construction and other consumer real estate 482 — 4 — 486 Bankcard and other revolving plans 478 — 3 — 481 Other 189 — 1 — 190 Total consumer loans 9,629 — 64 — 9,693 31 Total $ 40,564 $ 508 $ 1,573 $ 4 $ 42,649 $ 567
Summary Of Information On Impaired Loans	March 31, 2017 (In millions) Unpaid principal balance Recorded investment Total recorded investment Related allowance with no allowance with allowance Commercial: Commercial and industrial $ 460 $ 122 $ 285 $ 407 $ 40 Owner-occupied 126 55 57 112 3 Municipal 1 1 — 1 — Total commercial 587 178 342 520 43 Commercial real estate: Construction and land development 20 2 10 12 — Term 98 52 25 77 2 Total commercial real estate 118 54 35 89 2 Consumer: Home equity credit line 23 15 6 21 — 1-4 family residential 57 27 27 54 5 Construction and other consumer real estate 3 2 1 3 — Other 2 1 — 1 — Total consumer loans 85 45 34 79 5 Total $ 790 $ 277 $ 411 $ 688 $ 50 December 31, 2016 (In millions) Unpaid principal balance Recorded investment Total recorded investment Related allowance with no allowance with allowance Commercial: Commercial and industrial $ 470 $ 82 $ 311 $ 393 $ 52 Owner-occupied 115 71 30 101 3 Municipal 1 1 — 1 — Total commercial 586 154 341 495 55 Commercial real estate: Construction and land development 22 7 6 13 — Term 92 53 17 70 2 Total commercial real estate 114 60 23 83 2 Consumer: Home equity credit line 24 16 7 23 — 1-4 family residential 59 27 28 55 6 Construction and other consumer real estate 3 1 2 3 — Other 2 1 — 1 — Total consumer loans 88 45 37 82 6 Total $ 788 $ 259 $ 401 $ 660 $ 63 Three Months Ended Three Months Ended (In millions) Average recorded investment Interest income recognized Average recorded investment Interest income recognized Commercial: Commercial and industrial $ 393 $ 1 $ 282 $ 2 Owner-occupied 101 2 122 2 Municipal 1 — 1 — Total commercial 495 3 405 4 Commercial real estate: Construction and land development 13 — 15 1 Term 68 2 106 3 Total commercial real estate 81 2 121 4 Consumer: Home equity credit line 21 — 25 — 1-4 family residential 54 1 63 1 Construction and other consumer real estate 3 — 3 — Bankcard and other revolving plans — — — — Other 1 — 2 — Total consumer loans 79 1 93 1 Total $ 655 $ 6 $ 619 $ 9
Summary Of Selected Information On TDRs That Includes Recorded Investment On An Accruing And Nonaccruing Basis By Loan Class And Modification Type	March 31, 2017 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 $ 1 $ 29 $ — $ — $ — $ 36 $ 66 Owner-occupied 1 — 1 — 8 11 21 Total commercial 2 29 1 — 8 47 87 Commercial real estate: Construction and land development — 3 — — — 2 5 Term 5 — — 1 2 10 18 Total commercial real estate 5 3 — 1 2 12 23 Consumer: Home equity credit line — 2 10 — — 3 15 1-4 family residential 1 1 7 — 2 29 40 Construction and other consumer real estate — 1 — — — 1 2 Total consumer loans 1 4 17 — 2 33 57 Total accruing 8 36 18 1 12 92 167 Nonaccruing Commercial: Commercial and industrial 4 — 14 1 53 19 91 Owner-occupied 1 2 — 1 2 12 18 Municipal — 1 — — — — 1 Total commercial 5 3 14 2 55 31 110 Commercial real estate: Construction and land development — — — — 2 — 2 Term 2 1 — — 2 3 8 Total commercial real estate 2 1 — — 4 3 10 Consumer: Home equity credit line — — 1 — — — 1 1-4 family residential — 1 2 — 1 5 9 Construction and other consumer real estate — — — 1 — — 1 Total consumer loans — 1 3 1 1 5 11 Total nonaccruing 7 5 17 3 60 39 131 Total $ 15 $ 41 $ 35 $ 4 $ 72 $ 131 $ 298 December 31, 2016 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 $ — $ 19 $ — $ — $ — $ 28 $ 47 Owner-occupied 3 — 1 — 8 10 22 Total commercial 3 19 1 — 8 38 69 Commercial real estate: Construction and land development — 4 — — — 4 8 Term 4 — — 1 2 10 17 Total commercial real estate 4 4 — 1 2 14 25 Consumer: Home equity credit line — 1 10 — — 3 14 1-4 family residential 3 1 6 — 2 30 42 Construction and other consumer real estate — — — — — 1 1 Total consumer loans 3 2 16 — 2 34 57 Total accruing 10 25 17 1 12 86 151 Nonaccruing Commercial: Commercial and industrial 1 — — 1 33 25 60 Owner-occupied — 1 — 3 1 12 17 Municipal — 1 — — — — 1 Total commercial 1 2 — 4 34 37 78 Commercial real estate: Construction and land development — — — — 2 — 2 Term 2 1 — — 2 3 8 Total commercial real estate 2 1 — — 4 3 10 Consumer: Home equity credit line — — 1 — — 1 2 1-4 family residential — — 2 — 1 5 8 Construction and other consumer real estate — — — 2 — — 2 Total consumer loans — — 3 2 1 6 12 Total nonaccruing 3 3 3 6 39 46 100 Total $ 13 $ 28 $ 20 $ 7 $ 51 $ 132 $ 251 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.
Schedule Of Net Financial Impact On Interest Income Due To Interest Rate Modifications Below Market For Accruing TDR Loans
Schedule Of Outstanding Balances Of All Required Payments And The Related Carrying Amounts For PCI Loans	(In millions) March 31, 2017 December 31, 2016 Commercial $ 44 $ 49 Commercial real estate 47 51 Consumer 8 9 Outstanding balance $ 99 $ 109 Carrying amount $ 70 $ 77 Less ALLL 1 1 Carrying amount, net $ 69 $ 76
Schedule Of Changes In The Accretable Yield For PCI Loans	(In millions) Three Months Ended 2017 2016 Balance at beginning of period $ 33 $ 40 Accretion (4 ) (6 ) Reclassification from nonaccretable difference 2 8 Disposals and other 1 1 Balance at end of period $ 32 $ 43 Note: Amounts have been adjusted based on refinements to the original estimates of the accretable yield.

Derivative Instruments And He26

Derivative Instruments And Hedging Activities Derivative Instruments and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2017
Summary of Derivative Instruments [Abstract]
Schedule of Derivative Instruments	March 31, 2017 December 31, 2016 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: Interest rate swaps $ 1,388 $ 1 $ 3 $ 1,388 $ 2 $ 1 Derivatives not designated as hedging instruments Interest rate swaps and forwards 201 1 1 235 2 — Interest rate swaps for customers 1 4,106 44 45 4,162 49 49 Foreign exchange 438 9 7 424 11 9 Total derivatives not designated as hedging instruments 4,745 54 53 4,821 62 58 Total derivatives $ 6,133 $ 55 $ 56 $ 6,209 $ 64 $ 59 1 Notional amounts include both the customer swaps and the offsetting derivative contracts.
Schedule Of Gain (Loss) Of Derivative Instruments	Three Months Ended March 31, 2017 Three Months Ended March 31, 2016 Amount of derivative gain (loss) recognized/reclassified (In millions) OCI Reclassified from AOCI to interest income 2 Noninterest income (expense) Offset to interest expense OCI Reclassified from AOCI to interest income 2 Noninterest Offset to Derivatives designated as hedging instruments Cash flow hedges 1 : Interest rate swaps $ (2 ) $ 2 $ 21 $ 3 Derivatives not designated as hedging instruments Interest rate swaps and forward contracts $ (1 ) $ — Interest rate swaps for customers 1 — Foreign exchange 4 2 Total derivatives $ (2 ) $ 2 $ 4 $ — $ 21 $ 3 $ 2 $ — Note: These schedules are not intended to present at any given time the Company’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). 2 Amounts for the three months ended March 31 , of $2 million in 2017 and $3 million in 2016 , respectively, are the amounts of reclassification to earnings from AOCI presented in Note 8 .

Debt And Shareholders' Equity (

Debt And Shareholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2017
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, 2016 Subordinated notes $ 247 $ 247 Senior notes 135 287 Capital lease obligations 1 1 Total $ 383 $ 535
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 2017 2016 Affected line item Net unrealized gains on derivative instruments $ 2 $ 3 SI Interest and fees on loans Income tax expense 1 1 Amounts Reclassified from AOCI $ 1 $ 2 1 Negative reclassification amounts indicate decreases to earnings in the statement of income and increases to balance sheet assets. The opposite applies to positive reclassification amounts.
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, 2017 Balance at December 31, 2016 $ (93 ) $ 2 $ (31 ) $ (122 ) OCI before reclassifications, net of tax 12 — — 12 Amounts reclassified from AOCI, net of tax — (1 ) — (1 ) OCI (loss) 12 (1 ) — 11 Balance at March 31, 2017 $ (81 ) $ 1 $ (31 ) $ (111 ) Income tax expense (benefit) included in OCI (loss) $ 7 $ (1 ) $ — $ 6 Three Months Ended March 31, 2016 Balance at December 31, 2015 $ (18 ) $ 1 $ (38 ) $ (55 ) OCI before reclassifications, net of tax 32 14 (1 ) 45 Amounts reclassified from AOCI, net of tax — (2 ) — (2 ) OCI (loss) 32 12 (1 ) 43 Balance at March 31, 2016 $ 14 $ 13 $ (39 ) $ (12 ) Income tax expense included in OCI (loss) $ 20 $ 7 $ 1 $ 28

Debt And Shareholders' Equity S

Debt And Shareholders' Equity Schedule of Long-term Debt Instruments (Tables)	3 Months Ended
	Mar. 31, 2017
Debt Instrument [Line Items]
Schedule of Long-term Debt Instruments [Table Text Block]	Long-term debt is summarized as follows: (In millions) March 31, December 31, 2016 Subordinated notes $ 247 $ 247 Senior notes 135 287 Capital lease obligations 1 1 Total $ 383 $ 535

Commitments, Guarantees, And 29

Commitments, Guarantees, And Contingent Liabilities (Tables)	3 Months Ended
	Mar. 31, 2017
Guarantees, Commitments And Contingencies [Abstract]
Schedule Of Guarantees Issued	(In millions) March 31, December 31, Net unfunded commitments to extend credit 1 $ 18,467 $ 18,274 Standby letters of credit: Financial 701 771 Performance 191 196 Commercial letters of credit 77 60 Total unfunded lending commitments $ 19,436 $ 19,301 1 Net of participations

Retirement Plans (Tables)

Retirement Plans (Tables)	3 Months Ended
	Mar. 31, 2017
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Schedule Of Net Periodic Benefit Cost (Credit) For Pension And Postretirement Plans	Pension and Other Retirement Plans (In millions) Three Months Ended March 31, 2017 2016 Interest cost $ 2 $ 2 Expected return on plan assets (3 ) (3 ) Partial settlement loss 1 — Amortization of net actuarial gain 1 2 Net periodic benefit cost $ 1 $ 1

Operating Segment Information (

Operating Segment Information (Tables)	3 Months Ended
	Mar. 31, 2017
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 continues to be refined. Total average loans and deposits presented for the banking segments do not include intercompany amounts between banking segments, but may include deposits with the Other segment. Prior period amounts have been reclassified to reflect these changes. As of March 31, 2017 , 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 93 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 the Parent, Zions Management Services Company, 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. Throughout 2016 consolidation efforts continued, which resulted in transitioning full-time equivalents from the business segments to the Company’s back-office units. Due to the continuing nature and timing of this change, the Company’s back-office units retained more direct expenses in 2016 than in prior years. In the first quarter of 2017 we made changes to the FTP process and internal allocation of central expenses to better reflect the performance of business segments. Prior period amounts have been revised to reflect the impact of these changes had they been instituted in 2016. The following schedule does not present total assets or income tax expense for each operating segment, but instead presents average loans, average deposits and net income before income taxes because these are the metrics that management uses when evaluating performance and making decisions pertaining to the operating segments. The Parent’s net interest income includes interest expense on other 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 Company. 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, 2017 and 2016 : (In millions) Zions Bank Amegy CB&T NBAZ NSB 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 SELECTED INCOME STATEMENT DATA Net interest income $ 155 $ 150 $ 114 $ 113 $ 110 $ 103 $ 50 $ 45 $ 32 $ 30 Provision for loan losses 35 (31 ) 1 104 (5 ) (3 ) 1 2 (4 ) (26 ) Net interest income after provision for loan losses 120 181 113 9 115 106 49 43 36 56 Noninterest income 35 36 29 29 17 16 9 10 10 9 Noninterest expense 113 105 85 86 75 72 37 35 35 33 Net Income (loss) before taxes $ 42 $ 112 $ 57 $ (48 ) $ 57 $ 50 $ 21 $ 18 $ 11 $ 32 SELECTED AVERAGE BALANCE SHEET DATA Total loans $ 12,488 $ 12,306 $ 10,637 $ 10,370 $ 9,306 $ 8,905 $ 4,262 $ 3,863 $ 2,338 $ 2,263 Total deposits 16,268 15,700 11,318 11,274 10,921 10,479 4,661 4,445 4,211 4,011 (In millions) Vectra TCBW Other Consolidated Company 2017 2016 2017 2016 2017 2016 2017 2016 SELECTED INCOME STATEMENT DATA Net interest income $ 30 $ 30 $ 11 $ 9 $ (13 ) $ (27 ) $ 489 $ 453 Provision for loan losses (3 ) (3 ) (1 ) (2 ) (1 ) 1 23 42 Net interest income after provision for loan losses 33 33 12 11 (12 ) (28 ) 466 411 Noninterest income 6 6 1 1 25 10 132 117 Noninterest expense 25 23 5 5 39 37 414 396 Net Income (loss) before taxes $ 14 $ 16 $ 8 $ 7 $ (26 ) $ (55 ) $ 184 $ 132 SELECTED AVERAGE BALANCE SHEET DATA Total loans $ 2,535 $ 2,453 $ 877 $ 733 $ 123 $ 110 $ 42,566 $ 41,003 Total deposits 2,791 2,783 1,100 953 942 (90 ) 52,212 49,555
Schedule of Segment Reporting Information, by Segment	(In millions) Zions Bank Amegy CB&T NBAZ NSB 2017 2016 2017 2016 2017 2016 2017 2016 2017 2016 SELECTED INCOME STATEMENT DATA Net interest income $ 155 $ 150 $ 114 $ 113 $ 110 $ 103 $ 50 $ 45 $ 32 $ 30 Provision for loan losses 35 (31 ) 1 104 (5 ) (3 ) 1 2 (4 ) (26 ) Net interest income after provision for loan losses 120 181 113 9 115 106 49 43 36 56 Noninterest income 35 36 29 29 17 16 9 10 10 9 Noninterest expense 113 105 85 86 75 72 37 35 35 33 Net Income (loss) before taxes $ 42 $ 112 $ 57 $ (48 ) $ 57 $ 50 $ 21 $ 18 $ 11 $ 32 SELECTED AVERAGE BALANCE SHEET DATA Total loans $ 12,488 $ 12,306 $ 10,637 $ 10,370 $ 9,306 $ 8,905 $ 4,262 $ 3,863 $ 2,338 $ 2,263 Total deposits 16,268 15,700 11,318 11,274 10,921 10,479 4,661 4,445 4,211 4,011 (In millions) Vectra TCBW Other Consolidated Company 2017 2016 2017 2016 2017 2016 2017 2016 SELECTED INCOME STATEMENT DATA Net interest income $ 30 $ 30 $ 11 $ 9 $ (13 ) $ (27 ) $ 489 $ 453 Provision for loan losses (3 ) (3 ) (1 ) (2 ) (1 ) 1 23 42 Net interest income after provision for loan losses 33 33 12 11 (12 ) (28 ) 466 411 Noninterest income 6 6 1 1 25 10 132 117 Noninterest expense 25 23 5 5 39 37 414 396 Net Income (loss) before taxes $ 14 $ 16 $ 8 $ 7 $ (26 ) $ (55 ) $ 184 $ 132 SELECTED AVERAGE BALANCE SHEET DATA Total loans $ 2,535 $ 2,453 $ 877 $ 733 $ 123 $ 110 $ 42,566 $ 41,003 Total deposits 2,791 2,783 1,100 953 942 (90 ) 52,212 49,555

Basis of Presentaion (Details)

Basis of Presentaion (Details)	Mar. 31, 2017States
Basis Of Presentation [Abstract]
Number of States in which Entity Operates	11

Certain Recent Accounting Pro33

Certain Recent Accounting Pronouncements Certain Recent Accounting Pronouncements (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Operating Leases, Future Minimum Payments Due		$ 275
Income Tax Effects Allocated Directly to Equity, Cumulative Effect of Change in Accounting Principle	$ 4

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Other noninterest-bearing investments valued under the cost method	$ 12		$ 13
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	293		211
Net gains on sale of OREO properties	0	$ 1
Principal amount of other real estate owned property sold	2
Equity Method Investments, Fair Value Disclosure	38		35
OREO Properties [Member]
Derivatives, Fair Value [Line Items]
Net gains on sale of OREO properties		$ 2
Fair Value, Inputs, Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair value of AFS securities	15,473		13,188
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

Fair Value (Schedule Of Assets

Fair Value (Schedule Of Assets And Liabilities Measured At Fair Value By Class On A Recurring Basis) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Trading Securities	$ 40	$ 115
Other Assets, Fair Value Disclosure	95	91
Other Liabilities, Fair Value Disclosure	95	91
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	98	93
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	16,058	13,853
Financial and Nonfinancial Liabilities, Fair Value Disclosure	49	50
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Assets, Fair Value Disclosure	252	304
Financial and Nonfinancial Liabilities, Fair Value Disclosure	235	125
Mutual Funds And Stock Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	134	185
Bank-owned life insurance [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure	499	497
Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure	93	91
Interest-Only-Strip [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	20	20
Available-for-sale Securities [Member] | US Government Corporations and Agencies Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	14,163	12,009
Available-for-sale Securities [Member] | Municipal Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	1,285	1,154
Available-for-sale Securities [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	24
Asset-Backed Securities [Member] | Other Credit Derivatives [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		24
Derivative [Member] | Interest Rate Contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	2	4
Other Liabilities, Fair Value Disclosure	4	1
Derivative [Member] | Interest Rate Swaps [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	44	49
Other Liabilities, Fair Value Disclosure	45	49
Derivative [Member] | Foreign Exchange Contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	9	11
Other Liabilities, Fair Value Disclosure	7	9
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	15,473	13,188
Trading Securities	40	115
Financial Instruments Sold, Not yet Purchased, at Fair Value	0	0
Fair Value, Inputs, Level 2 [Member] | Mutual Funds And Stock Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	1	1
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	499	497
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
Fair Value, Inputs, Level 2 [Member] | Available-for-sale Securities [Member] | US Government Corporations and Agencies Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	14,163	12,009
Fair Value, Inputs, Level 2 [Member] | Available-for-sale Securities [Member] | Municipal Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	1,285	1,154
Fair Value, Inputs, Level 2 [Member] | Available-for-sale Securities [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	24
Fair Value, Inputs, Level 2 [Member] | Asset-Backed Securities [Member] | Other (Including ABS CDOs) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		24
Fair Value, Inputs, Level 2 [Member] | Derivative [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	46	53
Other Liabilities, Fair Value Disclosure	49	50
Fair Value, Inputs, Level 2 [Member] | Derivative [Member] | Interest Rate Contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	2	4
Other Liabilities, Fair Value Disclosure	4	1
Fair Value, Inputs, Level 2 [Member] | Derivative [Member] | Interest Rate Swaps [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	44	49
Other Liabilities, Fair Value Disclosure	45	49
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] | Private Equity Funds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Noninterest Bearing Investments Fair Value Disclosure	78	73
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	20	20
Fair Value, Inputs, Level 3 [Member] | Available-for-sale Securities [Member] | US Government Corporations and Agencies Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member] | Available-for-sale Securities [Member] | Municipal Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure
Fair Value, Inputs, Level 3 [Member] | Asset-Backed Securities [Member] | Other (Including ABS CDOs) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure
Fair Value, Inputs, Level 3 [Member] | Derivative [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	0	0
Other Liabilities, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	133	184
Other Assets, Fair Value Disclosure	95	91
Financial Instruments Sold, Not yet Purchased, at Fair Value	133	25
Other Liabilities, Fair Value Disclosure	95	91
Fair Value, Inputs, Level 1 [Member] | Mutual Funds And Stock Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	133	184
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	15	18
Fair Value, Inputs, Level 1 [Member] | Available-for-sale Securities [Member] | US Government Corporations and Agencies Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 [Member] | Derivative [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	9	11
Other Liabilities, Fair Value Disclosure	7	9
Fair Value, Inputs, Level 1 [Member] | Derivative [Member] | Foreign Exchange Contract [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	9	11
Other Liabilities, Fair Value Disclosure	$ 7	$ 9

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, 2017	Dec. 31, 2016
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Trading Securities	$ 40	$ 115
Other Assets, Fair Value Disclosure	95	91
Other Liabilities, Fair Value Disclosure	95	91
Estimate of Fair Value Measurement [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	15,606	13,372
Trading Securities	40	115
Assets, Fair Value Disclosure	16,408	14,250
Financial Instruments Sold, Not yet Purchased, at Fair Value	133	25
Financial and Nonfinancial Liabilities, Fair Value Disclosure	284	175
Estimate of Fair Value Measurement [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	55	64
Other Liabilities, Fair Value Disclosure	56	59
Interest Rate Contract [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	2	4
Other Liabilities, Fair Value Disclosure	4	1
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	98	93
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0	0
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	16,058	13,853
Financial and Nonfinancial Liabilities, Fair Value Disclosure	49	50
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	252	304
Financial and Nonfinancial Liabilities, Fair Value Disclosure	235	125
Foreign Exchange Contract [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	9	11
Other Liabilities, Fair Value Disclosure	7	9
Interest Rate Swap [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	44	49
Other Liabilities, Fair Value Disclosure	45	49
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	20	20
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	93	91
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	499	497
Mutual Funds And Stock Equity 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	134	185
Debt Securities [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	24
Other Credit Derivatives [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		24
US States and Political Subdivisions Debt Securities [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	1,285	1,154
US Government Corporations and Agencies Securities [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	14,163	12,009
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	15,473	13,188
Trading Securities	40	115
Financial Instruments Sold, Not yet Purchased, at Fair Value	0	0
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 Assets, Fair Value Disclosure	46	53
Other Liabilities, Fair Value Disclosure	49	50
Fair Value, Inputs, Level 2 [Member] | Interest Rate Contract [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	2	4
Other Liabilities, Fair Value Disclosure	4	1
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swap [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	44	49
Other Liabilities, Fair Value Disclosure	45	49
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
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	499	497
Fair Value, Inputs, Level 2 [Member] | Mutual Funds And Stock Equity 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	1
Fair Value, Inputs, Level 2 [Member] | Debt Securities [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	24
Fair Value, Inputs, Level 2 [Member] | US States and Political Subdivisions Debt Securities [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	1,285	1,154
Fair Value, Inputs, Level 2 [Member] | US Government Corporations and Agencies Securities [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	14,163	12,009
Fair Value, Inputs, Level 2 [Member] | Other (Including ABS CDOs) [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		24
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] | 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	0	0
Other Liabilities, 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	20	20
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	78	73
Fair Value, Inputs, Level 3 [Member] | US States and Political Subdivisions Debt Securities [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] | US Government Corporations and Agencies Securities [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	0	0
Fair Value, Inputs, Level 3 [Member] | Other (Including ABS CDOs) [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, 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	133	184
Other Assets, Fair Value Disclosure	95	91
Financial Instruments Sold, Not yet Purchased, at Fair Value	133	25
Other Liabilities, Fair Value Disclosure	95	91
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	9	11
Other Liabilities, Fair Value Disclosure	7	9
Fair Value, Inputs, Level 1 [Member] | Foreign Exchange Contract [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	9	11
Other Liabilities, Fair Value Disclosure	7	9
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	15	18
Fair Value, Inputs, Level 1 [Member] | Mutual Funds And Stock Equity 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	133	184
Fair Value, Inputs, Level 1 [Member] | US Government Corporations and Agencies Securities [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	$ 0	$ 0

Fair Value (Schedule Of Asset37

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, 2017	Mar. 31, 2016	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	$ 95		$ 91
Other Liabilities, Fair Value Disclosure	95		91
Total net gains (losses) included in, Other noninterest expense	51	$ 50
Private Equity Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets, Beginning balance	73	58
Total net gains (losses) included in, Dividends and other investment income
Total net gains (losses) included in, Equity securities gains, net	3	1
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases	7	2
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements	(5)
Fair value of assets, Ending balance	78	61
Servicing Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of liabilities, Beginning balance	20	14
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Noninterest Income		3
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements
Fair value of liabilities, Ending balance	20	$ 17
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	95		91
Other Liabilities, Fair Value Disclosure	$ 95		$ 91

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, 2017	Mar. 31, 2016	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	$ 95		$ 91
Other Liabilities, Fair Value Disclosure	95		$ 91
Level 3 Equity Securities Gains (Losses), Net [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Realized gains (losses) from Level 3 inputs	$ 3	$ 0

Fair Value Fair Value (Summary

Fair Value Fair Value (Summary of Quantitative Information Relating to the Principal Valuation Techniques and Significant Unobservable Inputs for Level 3) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Other Credit Derivatives [Member] | Asset-Backed Securities [Member]
Summary of Quantitative Information Relating to the Principal Valuation Techniques and Significant Unobservable Inputs for Level 3 [Line Items]
Investments, Fair Value Disclosure		$ 24
Fair Value, Inputs, Level 3 [Member]
Summary of Quantitative Information Relating to the Principal Valuation Techniques and Significant Unobservable Inputs for Level 3 [Line Items]
Investments, Fair Value Disclosure	$ 0	$ 0

Fair Value (Schedule Of Asset40

Fair Value (Schedule Of Assets With Fair Value Changes On Nonrecurring Basis) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Principal amount of other real estate owned property sold	$ 2
Fair value of assets measured on nonrecurring basis	2		$ 54
Gains (losses) from fair value changes	(2)	$ (15)
Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	1		52
Gains (losses) from fair value changes	(1)	(15)
Private Equity Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	1		1
Gains (losses) from fair value changes	(1)	$ 0
Other Real Estate Owned [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	0		1
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	0		0
Fair Value, Inputs, Level 1 [Member] | Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	0		0
Fair Value, Inputs, Level 1 [Member] | Private Equity Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	0		0
Fair Value, Inputs, Level 1 [Member] | Other Real Estate Owned [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	0		0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	1		53
Fair Value, Inputs, Level 2 [Member] | Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	1		52
Fair Value, Inputs, Level 2 [Member] | Private Equity Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	0		0
Fair Value, Inputs, Level 2 [Member] | Other Real Estate Owned [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	0		1
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	1		1
Fair Value, Inputs, Level 3 [Member] | Impaired Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	0		0
Fair Value, Inputs, Level 3 [Member] | Private Equity Investments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	1		1
Fair Value, Inputs, Level 3 [Member] | Other Real Estate Owned [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of assets measured on nonrecurring basis	$ 0		$ 0

Fair Value (Schedule Of Carryin

Fair Value (Schedule Of Carrying Values And Estimated Fair Values Of Financial Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
Held-to-maturity Securities	$ 815	$ 868
Held-to-maturity, fair value	803	850
Time deposits	2,994	2,757
Interest-bearing Deposit Liabilities, Foreign	0	0
Long-term debt (less fair value hedges)	383	535
Reported Value Measurement [Member]
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
Loans and leases (including loans held for sale), net of allowance	42,326	42,254
Other Short-term Borrowings	2,500	500
Long-term debt (less fair value hedges)	383	535
Estimate of Fair Value Measurement [Member]
Fair Value, Estimate Not Practicable, Financial Statement Captions [Line Items]
Loans and leases (including loans held for sale), net of allowance	42,038	42,111
Time deposits	2,977	2,744
Other Short-term Borrowings	2,500	500
Long-term debt (less fair value hedges)	$ 404	$ 552

Offsetting Assets and Liabili42

Offsetting Assets and Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Federal Funds Sold and Securities Borrowed or Purchased under Agreements to Resell [Member] | Assets [Member]
Offsetting Assets [Line Items]
Net amount	$ 363	$ 568
Gross amounts recognized	757	568
Gross amounts offset in the balance sheet	(394)	0
Net amounts presented in the balance sheet	363	568
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	38	47
Gross amounts recognized	55	64
Gross amounts offset in the balance sheet	0	0
Net amounts presented in the balance sheet	55	64
Gross amounts not offset in the balance sheet	(17)	(17)
Cash Collateral Received/Pledged	0	0
Assets, Total [Member] | Assets [Member]
Offsetting Assets [Line Items]
Net amount	401	615
Gross amounts recognized	812	632
Gross amounts offset in the balance sheet	(394)	0
Net amounts presented in the balance sheet	418	632
Gross amounts not offset in the balance sheet	(17)	(17)
Cash Collateral Received/Pledged	0	0
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member] | Other Liabilities [Member]
Offsetting Assets [Line Items]
Net amount	3,137	827
Gross amounts recognized	3,531	827
Gross amounts offset in the balance sheet	(394)	0
Net amounts presented in the balance sheet	3,137	827
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	25	25
Gross amounts recognized	56	59
Gross amounts offset in the balance sheet	0	0
Net amounts presented in the balance sheet	56	59
Gross amounts not offset in the balance sheet	(17)	(17)
Cash Collateral Received/Pledged	(14)	(17)
Liabilities, Total [Member] | Other Liabilities [Member]
Offsetting Assets [Line Items]
Net amount	3,162	852
Gross amounts recognized	3,587	886
Gross amounts offset in the balance sheet	(394)	0
Net amounts presented in the balance sheet	3,193	886
Gross amounts not offset in the balance sheet	(17)	(17)
Cash Collateral Received/Pledged	$ (14)	$ (17)

Investment Securities (Narrativ

Investment Securities (Narrative) (Details) $ in Millions	Mar. 31, 2017USD ($)Securitiesyr	Mar. 31, 2017USD ($)Securities	Dec. 31, 2016USD ($)Securities	Mar. 31, 2017USD ($)Securities
Investment [Line Items]
Private equity investments prohibited by Volker rule	$ 5	$ 5		$ 5
Number of HTM investment securities in an unrealized loss position | Securities	453	453	642	453
Number of AFS investment securities in an unrealized loss position | Securities	2,121	2,121	2,398	2,121
Carrying value of pledged securities	$ 2,100	$ 2,100	$ 1,400	$ 2,100
Private Equity Investments	143	143		143
Private Equity Investments Sold Prohibited by Volcker Rule		1	10	11
Commitments for Private Equity and Other Noninterest-bearing Investments	24	24		24
Commitments for Private Equity or Other Non-Interest Bearing Investments Prohibited by the Volcker Rule	$ 3	3		3
Small Business Administration Loan-Backed Securities [Member] | Minimum [Member]
Investment [Line Items]
Investment term of maturity | yr	5
Small Business Administration Loan-Backed Securities [Member] | Maximum [Member]
Investment [Line Items]
Investment term of maturity | yr	25
US States and Political Subdivisions Debt Securities [Member]
Investment [Line Items]
Held-to-maturity, Amortized cost	$ 815	$ 815	$ 868	$ 815

Investment Securities (Summary

Investment Securities (Summary Of Investment Securities) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Investment [Line Items]
Held-to-maturity, fair value	$ 803	$ 850
Available-for-sale Debt Securities, Amortized Cost Basis	15,602	13,337
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	27	18
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	157	167
Available-for-sale debt securities, Estimated fair value	15,472	13,188
Available-for-sale Securities, Gross Unrealized Gain	27	18
Available-for-sale, Amortized cost	15,736	13,521
Available-for-sale, Gross unrealized losses, Recognized in OCI	157	167
Available-for-sale securities, Estimated fair value	15,606	13,372
amortized cost of investment securities	16,551	14,389
Gross Unrealized Gains of Investment Securities Recognized in OCI	34	23
Gross Unrealized Losses of Investment Securities Recognized in OCI	176	190
Estimated Fair Value of Investment Securities	16,409	14,222
Mutual Funds And Stock [Member]
Investment [Line Items]
Available-for-sale Securities, Gross Unrealized Gain	0	0
Available-for-sale, Amortized cost	134	184
Available-for-sale, Gross unrealized losses, Recognized in OCI	0	0
Available-for-sale securities, Estimated fair value	134	184
US States and Political Subdivisions Debt Securities [Member]
Investment [Line Items]
Held-to-maturity, fair value	803	850
Held-to-maturity, Amortized cost	815	868
Available-for-sale Debt Securities, Amortized Cost Basis	1,299	1,182
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	4	1
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	18	29
Available-for-sale debt securities, Estimated fair value	1,285	1,154
Held-to-maturity Securities, Unrecognized Holding Gain	7	5
Held-to-maturity Securities, Unrecognized Holding Loss	19	23
Available-for-sale Securities [Member]
Investment [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	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	1	1
Available-for-sale debt securities, Estimated fair value	24	24
Agency Securities [Member]
Investment [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	1,858	1,846
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	3	2
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	8	9
Available-for-sale debt securities, Estimated fair value	1,853	1,839
Agency Guaranteed Mortgage-Backed Securities [Member]
Investment [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	10,060	7,986
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	12	7
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	111	110
Available-for-sale debt securities, Estimated fair value	9,961	7,883
Small Business Administration Loan-Backed Securities [Member]
Investment [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	2,360	2,298
Available-For-Sale Debt Securities, Gross Unrealized Gains, Recognized In O C I	8	8
Available-For-Sale Debt Securities, Gross Unrealized Losses, Recognized In O C I	19	18
Available-for-sale debt securities, Estimated fair value	$ 2,349	$ 2,288

Investment Securities (Contract

Investment Securities (Contractual Maturities Debt Securities) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Investments [Abstract]
Held-to-maturity Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost	$ 142
Held-to-maturity, Due in one year or less, Estimated fair value	142
Held-to-maturity, Due after one year through five years, Amortized cost	273
Held-to-maturity, Due after one year through five years, Estimated fair value	274
Held-to-maturity, Due after five years through ten years, Amortized cost	196
Held-to-maturity, Due after five years through ten years, Estimated fair value	196
Held-to-maturity Securities, Debt Maturities, Rolling after Ten Years, Amortized Cost	204
Held-to-maturity, Due after ten years, Estimated fair value	191
Held-to-maturity, Amortized cost	815
Held-to-maturity, fair value	803	$ 850
Available-for-sale, Due in one year or less, Amortized cost	1,884
Available-for-sale, Due in one year or less, Estimated fair value	1,868
Available-for-sale, Due after one year through five years, Amortized cost	5,875
Available-for-sale, Due after one year through five years, Estimated fair value	5,828
Available-for-sale, Due after five years through ten years, Amortized cost	4,904
Available-for-sale, Due after five years through ten years, Estimated fair value	4,860
Available-for-sale, Due after ten years, Amortized cost	2,939
Available-for-sale, Due after ten years, Estimated fair value	2,916
Available-for-sale, Amortized cost	15,602	13,337
Available-for-sale, Estimated fair value	$ 15,472	$ 13,188

Investment Securities (Summar46

Investment Securities (Summary Of Amount Of Gross Unrealized Losses For Debt Securities And Estimated Fair Value) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Investment [Line Items]
Investment Securities Gross Unrealized Losses Less Than 12 Months	$ 141	$ 157
Investment Securities Estimated Fair Value Less Than 12 Months	10,184	9,585
Investment Securities Gross Unrealized Losses 12 Months or More	35	33
Investment Securities Estimated Fair Value 12 Months or More	1,517	1,378
Investment Securities Gross Unrealized Losses Total	176	190
Investment Securities Estimated Fair Value Total	11,701	10,963
US States and Political Subdivisions Debt Securities [Member]
Investment [Line Items]
Held-to-maturity, Less than 12 months - Gross unrealized losses	10	15
Held-to-maturity, Less than 12 months - Estimated fair value	309	467
Held-to-maturity, 12 months or more - Gross unrealized losses	9	8
Held-to-maturity, 12 months or more - Estimated fair value	128	61
Held-to-maturity, Total - Gross unrealized losses	19	23
Held-to-maturity, Total - Estimated fair value	437	528
Available-for-sale, Less than 12 months - Gross unrealized losses	17	28
Available-for-sale, Less than 12 months - Estimated fair value	811	992
Available-for-sale, 12 months or more - Gross unrealized losses	1	0
Available-for-sale, 12 months or more - Estimated fair value	14	9
Available-for-sale, Total - Gross unrealized losses	18	28
Available-for-sale, Total - Estimated fair value	825	1,001
Agency Securities [Member]
Investment [Line Items]
Available-for-sale, Less than 12 months - Gross unrealized losses	7	9
Available-for-sale, Less than 12 months - Estimated fair value	1,297	950
Available-for-sale, 12 months or more - Gross unrealized losses	1	0
Available-for-sale, 12 months or more - Estimated fair value	124	127
Available-for-sale, Total - Gross unrealized losses	8	9
Available-for-sale, Total - Estimated fair value	1,421	1,077
Agency Guaranteed Mortgage-Backed Securities [Member]
Investment [Line Items]
Available-for-sale, Less than 12 months - Gross unrealized losses	103	102
Available-for-sale, Less than 12 months - Estimated fair value	7,220	6,649
Available-for-sale, 12 months or more - Gross unrealized losses	8	7
Available-for-sale, 12 months or more - Estimated fair value	440	326
Available-for-sale, Total - Gross unrealized losses	111	109
Available-for-sale, Total - Estimated fair value	7,660	6,975
Small Business Administration Loan-Backed Securities [Member]
Investment [Line Items]
Available-for-sale, Less than 12 months - Gross unrealized losses	4	3
Available-for-sale, Less than 12 months - Estimated fair value	547	527
Available-for-sale, 12 months or more - Gross unrealized losses	15	16
Available-for-sale, 12 months or more - Estimated fair value	798	841
Available-for-sale, Total - Gross unrealized losses	19	19
Available-for-sale, Total - Estimated fair value	1,345	1,368
Available-for-sale, Unrealized losses, Other [Member]
Investment [Line Items]
Available-for-sale, Less than 12 months - Gross unrealized losses	0	0
Available-for-sale, Less than 12 months - Estimated fair value	0	0
Available-for-sale, 12 months or more - Gross unrealized losses	1	2
Available-for-sale, 12 months or more - Estimated fair value	13	14
Available-for-sale, Total - Gross unrealized losses	1	2
Available-for-sale, Total - Estimated fair value	13	14
Available-for-sale Securities [Member]
Investment [Line Items]
Available-for-sale, Less than 12 months - Gross unrealized losses	131	142
Available-for-sale, Less than 12 months - Estimated fair value	9,875	9,118
Available-for-sale, 12 months or more - Gross unrealized losses	26	25
Available-for-sale, 12 months or more - Estimated fair value	1,389	1,317
Available-for-sale, Total - Gross unrealized losses	157	167
Available-for-sale, Total - Estimated fair value	$ 11,264	$ 10,435

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, 2017	Mar. 31, 2016
Investments [Abstract]
Investment securities, Held-to-maturity, Gross gains	$ 0	$ 0
Other than Temporary Impairment Losses, Investments, Held-to-maturity Securities	0	0
Investment securities, Available-for-sale, Gross gains	0	0
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities	0	0
Other noninterest-bearing investments, Nonmarketable equity securities, Gross gains	10	3
Other noninterest-bearing investments, Nonmarketable equity securities, Gross losses	5	3
Total investment securities and other noninterest-bearing investments, Gross gains	10	3
Total investment securities and other noninterest-bearing investments, Gross losses	5	3
Net losses	5	0
Gain (Loss) on Sale of Equity Investments	$ 5	$ 0

Investment Securities Taxable a

Investment Securities Taxable and Nontaxable Interest Income by Investment Type (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Noninterest Income	$ 78	$ 47
Taxable [Member]
Noninterest Income	69	42
Nontaxable [Member]
Noninterest Income	9	5
Held-to-maturity Securities [Member]
Noninterest Income	7	5
Held-to-maturity Securities [Member] | Taxable [Member]
Noninterest Income	3	2
Held-to-maturity Securities [Member] | Nontaxable [Member]
Noninterest Income	4	3
Available-for-sale Securities [Member]
Noninterest Income	71	42
Available-for-sale Securities [Member] | Taxable [Member]
Noninterest Income	66	40
Available-for-sale Securities [Member] | Nontaxable [Member]
Noninterest Income	$ 5	$ 2

Loans And Allowance For Credi49

Loans And Allowance For Credit Losses (Narrative) (Details)		3 Months Ended		12 Months Ended
		Mar. 31, 2017USD ($)dBilling_CyclesmoPayments	Mar. 31, 2016USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Mar. 31, 2016USD ($)
Loans And Allowance For Credit Losses [Line Items]
Unfunded Lending Commitments on Troubled Debt Restructuring		$ 19,000,000		$ 19,000,000	$ 14,000,000
Loans and Leases Receivable, Gross		42,742,000,000		42,742,000,000	42,649,000,000
Financing Receivable, Recorded Investment, Current		42,353,000,000		42,353,000,000	42,340,000,000
Threshold for Internal risk grades assigned to commercial and commercial real estate loans		750,000		750,000
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		18,000,000	$ 7,000,000	129,000,000		$ 180,000,000
Unearned income and fees, net of related costs		69,000,000		69,000,000	77,000,000
Owner occupied and commercial real estate loans, unamortized premiums		18,000,000		18,000,000	20,000,000
Land Development Loans		283,000,000		283,000,000	290,000,000
Loans at carrying value pledged as collateral for current and potential borrowings		22,200,000,000		22,200,000,000	24,000,000,000
Payments for Origination and Purchases of Loans Held-for-sale		303,000,000	236,000,000
Principal Balance of Loans Sold, Serviced Loans		2,000,000,000			2,000,000,000
Loans and Leases Receivable, Gain (Loss) on Sales, Net		4,000,000	3,000,000
Principle amount of loans held for sale sold		$ 316,000,000	273,000,000
Number of days for consumer loans to be charged off | d		180
Number of days for closed-end loans to be charged off | d		120
Minimum number of days past due for nonaccrual status | d		90
Minimum number of monthly payments in arrears when reporting past due | Payments		2
Minimum number of billing cycles in arrears when reported as past due | Billing_Cycles		2
Minimum number of days unpaid when reported as past due | d		30
Threshold for nonaccrual loans for evaluation of impairment		$ 1,000,000
Minimum number of months for borrower to meet terms For TDR status | mo		6
Recorded investment in TDR loans modified with interest rates below market		$ 133,000,000		133,000,000	128,000,000
Additional interest income due to increased cash flows from acquired loans		3,000,000	4,000,000
Provision for Loan and Lease Losses		23,000,000	42,000,000
Provision for Unfunded Lending Commitments		5,000,000	6,000,000
Other Real Estate, Foreclosed Assets, and Repossessed Assets		2,000,000		2,000,000
Other Real Estate, In Process of Forecloseing Assets		13,000,000		13,000,000	10,000,000
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		197,000,000		197,000,000	150,000,000
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		192,000,000		192,000,000	159,000,000
Financing Receivable, Recorded Investment, Past Due		389,000,000		389,000,000	309,000,000
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		30,000,000		30,000,000	36,000,000
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	331,000,000		331,000,000	381,000,000
Commercial [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		$ 21,556,000,000		21,556,000,000	21,615,000,000
Subsequent payment default period, number of days | d		90
Provision for Loan and Lease Losses		$ 22,000,000	46,000,000
Provision for Unfunded Lending Commitments		4,000,000	(2,000,000)
Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		$ 9,980,000,000		9,980,000,000	9,693,000,000
Subsequent payment default period, number of days | d		60
Provision for Loan and Lease Losses		$ 4,000,000	(6,000,000)
Provision for Unfunded Lending Commitments		0	0
Consumer Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		9,980,000,000		9,980,000,000	9,693,000,000
Financing Receivable, Recorded Investment, Current		9,925,000,000		9,925,000,000	9,638,000,000
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		28,000,000		28,000,000	22,000,000
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		27,000,000		27,000,000	33,000,000
Financing Receivable, Recorded Investment, Past Due		55,000,000		55,000,000	55,000,000
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		4,000,000		4,000,000	5,000,000
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	15,000,000		15,000,000	17,000,000
Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		181,000,000		181,000,000	190,000,000
Financing Receivable, Recorded Investment, Current		180,000,000		180,000,000	189,000,000
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		1,000,000		1,000,000	1,000,000
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0		0	0
Financing Receivable, Recorded Investment, Past Due		1,000,000		1,000,000	1,000,000
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0	0
Finance Leases Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		404,000,000		404,000,000	423,000,000
Financing Receivable, Recorded Investment, Current		401,000,000		401,000,000	423,000,000
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		2,000,000		2,000,000	0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		1,000,000		1,000,000	0
Financing Receivable, Recorded Investment, Past Due		3,000,000		3,000,000	0
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	11,000,000		11,000,000	14,000,000
Owner Occupied [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		6,973,000,000		6,973,000,000	6,962,000,000
Financing Receivable, Recorded Investment, Current		6,880,000,000		6,880,000,000	6,894,000,000
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		59,000,000		59,000,000	40,000,000
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		34,000,000		34,000,000	28,000,000
Financing Receivable, Recorded Investment, Past Due		93,000,000		93,000,000	68,000,000
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		3,000,000		3,000,000	8,000,000
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	35,000,000		35,000,000	43,000,000
Municipal [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		811,000,000		811,000,000	778,000,000
Financing Receivable, Recorded Investment, Current		811,000,000		811,000,000	778,000,000
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		0		0	0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0		0	0
Financing Receivable, Recorded Investment, Past Due		0		0	0
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	1,000,000		1,000,000	1,000,000
Commercial Loan [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		21,556,000,000		21,556,000,000	21,615,000,000
Financing Receivable, Recorded Investment, Current		21,268,000,000		21,268,000,000	21,401,000,000
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		155,000,000		155,000,000	112,000,000
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		133,000,000		133,000,000	102,000,000
Financing Receivable, Recorded Investment, Past Due		288,000,000		288,000,000	214,000,000
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		12,000,000		12,000,000	18,000,000
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	292,000,000		292,000,000	345,000,000
Commercial Real Estate Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		2,123,000,000		2,123,000,000	2,019,000,000
Financing Receivable, Recorded Investment, Current		2,113,000,000		2,113,000,000	2,010,000,000
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		3,000,000		3,000,000	7,000,000
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		7,000,000		7,000,000	2,000,000
Financing Receivable, Recorded Investment, Past Due		10,000,000		10,000,000	9,000,000
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0		0	1,000,000
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0	1,000,000
Term [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		9,083,000,000		9,083,000,000	9,322,000,000
Financing Receivable, Recorded Investment, Current		9,047,000,000		9,047,000,000	9,291,000,000
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		11,000,000		11,000,000	9,000,000
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		25,000,000		25,000,000	22,000,000
Financing Receivable, Recorded Investment, Past Due		36,000,000		36,000,000	31,000,000
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		14,000,000		14,000,000	12,000,000
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24,000,000		24,000,000	18,000,000
Commercial Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		11,206,000,000		11,206,000,000	11,341,000,000
Financing Receivable, Recorded Investment, Current		11,160,000,000		11,160,000,000	11,301,000,000
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		14,000,000		14,000,000	16,000,000
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		32,000,000		32,000,000	24,000,000
Financing Receivable, Recorded Investment, Past Due		46,000,000		46,000,000	40,000,000
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		14,000,000		14,000,000	13,000,000
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24,000,000		24,000,000	19,000,000
Home Equity Line of Credit [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		2,638,000,000		2,638,000,000	2,645,000,000
Financing Receivable, Recorded Investment, Current		2,626,000,000		2,626,000,000	2,635,000,000
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		7,000,000		7,000,000	4,000,000
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		5,000,000		5,000,000	6,000,000
Financing Receivable, Recorded Investment, Past Due		12,000,000		12,000,000	10,000,000
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		2,000,000		2,000,000	1,000,000
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	4,000,000		4,000,000	5,000,000
One Through Four Family Residential [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		6,185,000,000		6,185,000,000	5,891,000,000
Financing Receivable, Recorded Investment, Current		6,156,000,000		6,156,000,000	5,857,000,000
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		11,000,000		11,000,000	12,000,000
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		18,000,000		18,000,000	22,000,000
Financing Receivable, Recorded Investment, Past Due		29,000,000		29,000,000	34,000,000
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	11,000,000		11,000,000	11,000,000
Construction And Other Consumer Real Estate [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		517,000,000		517,000,000	486,000,000
Financing Receivable, Recorded Investment, Current		509,000,000		509,000,000	479,000,000
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		6,000,000		6,000,000	3,000,000
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		2,000,000		2,000,000	4,000,000
Financing Receivable, Recorded Investment, Past Due		8,000,000		8,000,000	7,000,000
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1,000,000		1,000,000	3,000,000
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0	0
Revolving Credit Facility [Member]
Loans And Allowance For Credit Losses [Line Items]
Loans and Leases Receivable, Gross		459,000,000		459,000,000	481,000,000
Financing Receivable, Recorded Investment, Current		454,000,000		454,000,000	478,000,000
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		3,000,000		3,000,000	2,000,000
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		2,000,000		2,000,000	1,000,000
Financing Receivable, Recorded Investment, Past Due		5,000,000		5,000,000	3,000,000
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1,000,000		1,000,000	1,000,000
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0	1,000,000
Accruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		167,000,000		167,000,000	151,000,000
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	4,000,000
Nonaccruing [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		298,000,000		298,000,000	251,000,000
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		18,000,000	$ 3,000,000
Nonaccruing [Member] | Consumer Portfolio Segment [Member]
Loans And Allowance For Credit Losses [Line Items]
Financing Receivable, Modifications, Recorded Investment		$ 11,000,000		$ 11,000,000	$ 12,000,000
[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 Credi50

Loans And Allowance For Credit Losses (Summary Of Major Portfolio Segment And Specific Loan Class) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Balance at end of period	$ 544	$ 612
Loans held for sale	128		$ 172
Commercial and industrial	13,368		13,452
Leasing	404		423
Owner occupied	6,973		6,962
Municipal	811		778
Construction and land development	2,123		2,019
Term	9,083		9,322
Provision for loan losses	(23)	(42)
Allowance for Loan and Lease Losses, Write-offs	(57)	(48)
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	11	12
Net loan and lease charge-offs	(46)	(36)
Reserve for unfunded lending commitments	60	69	65	$ 75
Provision for Unfunded Lending Commitments	5	6
Total allowance for credit losses	604	$ 681
Loans Receivable, Gross, Commercial, Real Estate	11,206		11,341
Loans and Leases Receivable, Gross, Consumer, Home Equity	2,638		2,645
Loans and Leases Receivable, Gross, Consumer, Mortgage	6,185		5,891
Loans and Leases Receivable, Gross, Consumer, Construction	517		486
Loans and Leases Receivable, Gross, Consumer, Revolving, Credit Card	459		481
Loans and Leases Receivable, Gross, Consumer, Other	181		190
Loans and Leases Receivable, Gross	42,742		42,649
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable before Fees, Gross	21,556		21,615
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable before Fees, Gross	$ 9,980		$ 9,693

Loans And Allowance For Credi51

Loans And Allowance For Credit Losses (Summary Of Changes In The Allowance For Credit Losses) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	$ (23)	$ (42)
Allowance for Loan and Lease Losses, Write-offs	(57)	(48)
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	567	606
Allowance for Loan and Lease Losses, Adjustments, Other	(46)	(36)
Balance at end of period	60	69
Allowance for loan losses	567	606	$ 544	$ 567	$ 612	$ 606
Reserve for unfunded lending commitments	60	69	60	65	69	75
Total allowance for credit losses			604		681
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	11	12
Provision for Unfunded Lending Commitments	(5)	(6)
Balance at end of period	544	612
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	(22)	(46)
Allowance for Loan and Lease Losses, Write-offs	(51)	43
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	420	454
Allowance for Loan and Lease Losses, Adjustments, Other	(45)	(36)
Balance at end of period	50	56
Allowance for loan losses	420	454	397	420	464	454
Reserve for unfunded lending commitments	50	56	50	54	56	58
Total allowance for credit losses			447		520
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	6	7
Provision for Unfunded Lending Commitments	(4)	2
Balance at end of period	397	464
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	3	(2)
Allowance for Loan and Lease Losses, Write-offs	(1)	1
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	116	114
Allowance for Loan and Lease Losses, Adjustments, Other	1	2
Balance at end of period	10	13
Allowance for loan losses	116	114	114	116	118	114
Reserve for unfunded lending commitments	10	13	10	11	13	17
Total allowance for credit losses			124		131
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	2	3
Provision for Unfunded Lending Commitments	(1)	4
Balance at end of period	114	118
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan and Lease Losses, Provision for Loss, Gross	(4)	6
Allowance for Loan and Lease Losses, Write-offs	(5)	4
Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	31	38
Allowance for Loan and Lease Losses, Adjustments, Other	(2)	(2)
Balance at end of period	0	0
Allowance for loan losses	31	38	33	31	30	38
Reserve for unfunded lending commitments	0	0	0	$ 0	0	$ 0
Total allowance for credit losses			$ 33		$ 30
Allowance for Loan and Lease Losses, Recoveries of Bad Debts	3	2
Provision for Unfunded Lending Commitments	0	0
Balance at end of period	$ 33	$ 30

Loans And Allowance For Credi52

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, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$ 655	$ 619
Impaired Financing Receivable, Interest Income, Accrual Method	6	9
Allowance for loan losses: Individually evaluated for impairment	(51)		$ (65)
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	492		502
Outstanding loan balances: Individually evaluated for impairment	645		619
Outstanding loan balances: Collectively evaluated for impairment	42,026		41,953
Certain Loans and Debt Securities Acquired in Transfer, with Related Allowance for Credit Losses Due to Subsequent Impairment	71		77
Loans and Leases Receivable, Gross	42,742		42,649
Financing Receivable Allowance For Credit Losses and Receivables Acquired With Deteriorated Credit Quality	1		0
Loans and Leases Receivable, Allowance	544	612	567	$ 606
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	101	122
Impaired Financing Receivable, Interest Income, Accrual Method	2	2
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses: Individually evaluated for impairment	(43)		(56)
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	354		364
Outstanding loan balances: Individually evaluated for impairment	490		466
Outstanding loan balances: Collectively evaluated for impairment	21,033		21,111
Certain Loans and Debt Securities Acquired in Transfer, with Related Allowance for Credit Losses Due to Subsequent Impairment	33		38
Loans and Leases Receivable, Gross	21,556		21,615
Financing Receivable Allowance For Credit Losses and Receivables Acquired With Deteriorated Credit Quality	0		0
Loans and Leases Receivable, Allowance	397	464	420	454
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	13	15
Impaired Financing Receivable, Interest Income, Accrual Method	0	1
Loans and Leases Receivable, Allowance	114	118	116	114
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	1	2
Impaired Financing Receivable, Interest Income, Accrual Method	0	0
Allowance for loan losses: Individually evaluated for impairment	(5)		(6)
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	27		25
Outstanding loan balances: Individually evaluated for impairment	73		75
Outstanding loan balances: Collectively evaluated for impairment	9,900		9,611
Certain Loans and Debt Securities Acquired in Transfer, with Related Allowance for Credit Losses Due to Subsequent Impairment	7		7
Loans and Leases Receivable, Gross	9,980		9,693
Financing Receivable Allowance For Credit Losses and Receivables Acquired With Deteriorated Credit Quality	1		0
Loans and Leases Receivable, Allowance	33	30	31	$ 38
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	495	405
Impaired Financing Receivable, Interest Income, Accrual Method	3	4
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	68	106
Impaired Financing Receivable, Interest Income, Accrual Method	2	3
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	81	121
Impaired Financing Receivable, Interest Income, Accrual Method	2	4
Allowance for loan losses: Individually evaluated for impairment	(3)		(3)
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment	111		113
Outstanding loan balances: Individually evaluated for impairment	82		78
Outstanding loan balances: Collectively evaluated for impairment	11,093		11,231
Certain Loans and Debt Securities Acquired in Transfer, with Related Allowance for Credit Losses Due to Subsequent Impairment	31		32
Loans and Leases Receivable, Gross	11,206		11,341
Financing Receivable Allowance For Credit Losses and Receivables Acquired With Deteriorated Credit Quality	0		0
Loans and Leases Receivable, Allowance	114		$ 116
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	21	25
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	54	63
Impaired Financing Receivable, Interest Income, Accrual Method	1	1
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	3	3
Impaired Financing Receivable, Interest Income, Accrual Method	0	0
Revolving Credit Facility [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
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Impaired Financing Receivable, Average Recorded Investment	79	93
Impaired Financing Receivable, Interest Income, Accrual Method	1	1
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

Loans And Allowance For Credi53

Loans And Allowance For Credit Losses (Summary Of Nonaccrual Loans) (Details) - USD ($) $ in Millions		Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Total	[1]	$ 331	$ 381
loans held for sale [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		34	40
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		7	7
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		13	14
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		89	74
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		461	443
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		38	29
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		45	36
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		9	11
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		35	36
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		1	2
Revolving Credit Facility [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		0	1
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		45	50
Financing Receivables, Total [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		551	529
Commercial and Industrial Sector [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total		$ 358	$ 354
[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 Credi54

Loans And Allowance For Credit Losses (Summary Of Past Due Loans (Accruing And Nonaccruing)) (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
		Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 18	$ 7	$ 129	$ 180
Financing Receivable, Recorded Investment, Current		42,353		42,353		$ 42,340
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		197		197		150
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		192		192		159
Total past due		389		389		309
Loans and Leases Receivable, Gross		42,742		42,742		42,649
Accruing loans 90+ days past due		30		30		36
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	331		331		381
LoansReceivableHeldForSaleNet [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current						172
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due						0
Total past due						0
Loans and Leases Receivable, Gross						172
Accruing loans 90+ days past due						0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]					40
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		14	3
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		21,556		21,556		21,615
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		16	7
Financing Receivable, Recorded Investment, Nonaccrual Status		461		461		443
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		7		7		7
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		9,980		9,980		9,693
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		45		45		50
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		13		13		14
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	4
Financing Receivable, Recorded Investment, Nonaccrual Status		89		89		74
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		1		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		38		38		29
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		11,206		11,206		11,341
Financing Receivable, Recorded Investment, Nonaccrual Status		45		45		36
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		9		9		11
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		35		35		36
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		1		1		2
Revolving Credit Facility [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		0		$ 0		$ 1
Accruing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	4
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	4
Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	4
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	0
Nonaccruing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		18	3
Nonaccruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		14	3
Nonaccruing [Member] | Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		16	3
Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	0
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	$ 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 Credi55

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		12 Months Ended
		Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 18	$ 7	$ 129	$ 180
Financing Receivable, Recorded Investment, Current		42,353		42,353		$ 42,340
Loans held for sale		128		128		172
Commercial and industrial		13,368		13,368		13,452
Leasing		404		404		423
Owner occupied		6,973		6,973		6,962
Municipal		811		811		778
Construction and land development		2,123		2,123		2,019
Term		9,083		9,083		9,322
Loans Receivable, Gross, Commercial, Real Estate		11,206		11,206		11,341
Loans and Leases Receivable, Gross, Consumer, Home Equity		2,638		2,638		2,645
1-4 family residential		6,185		6,185		5,891
Loans and Leases Receivable, Gross, Consumer, Construction		517		517		486
Bankcard and other revolving plans		459		459		481
Other		181		181		190
Loans and Leases Receivable, Gross		42,742		42,742		42,649
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		197		197		150
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		192		192		159
Financing Receivable, Recorded Investment, Past Due		389		389		309
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		30		30		36
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	331		331		381
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable before Fees, Gross		9,980		9,980		9,693
Loans and Leases Receivable, Gross, Consumer, Home Equity		2,638		2,638		2,645
1-4 family residential		6,185		6,185		5,891
Loans and Leases Receivable, Gross, Consumer, Construction		517		517		486
Bankcard and other revolving plans		459		459		481
Other		181		181		190
Loans and Leases Receivable, Gross		9,980		9,980		9,693
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Construction and land development		2,123		2,123		2,019
Term		9,083		9,083		9,322
Loans Receivable, Gross, Commercial, Real Estate		11,206		11,206		11,341
Financing Receivable, Recorded Investment, Nonaccrual Status		7		7		7
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Commercial and industrial		13,368		13,368		13,452
Leasing		404		404		423
Owner occupied		6,973		6,973		6,962
Municipal		811		811		778
Loans and Leases Receivable before Fees, Gross		21,556		21,556		21,615
Loans and Leases Receivable, Gross		21,556		21,556		21,615
Pass [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		40,730		40,730		40,564
Pass [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable before Fees, Gross		9,915		9,915		9,629
Loans and Leases Receivable, Gross, Consumer, Home Equity		2,620		2,620		2,629
1-4 family residential		6,143		6,143		5,851
Loans and Leases Receivable, Gross, Consumer, Construction		515		515		482
Bankcard and other revolving plans		457		457		478
Other		180		180		189
Pass [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Construction and land development		2,043		2,043		1,942
Term		8,843		8,843		9,096
Loans Receivable, Gross, Commercial, Real Estate		10,886		10,886		11,038
Pass [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Commercial and industrial		12,175		12,175		12,185
Leasing		376		376		387
Owner occupied		6,573		6,573		6,560
Municipal		805		805		765
Loans and Leases Receivable before Fees, Gross		19,929		19,929		19,897
Special Mention [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		548		548		508
Special Mention [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable before Fees, Gross		0		0		0
Loans and Leases Receivable, Gross, Consumer, Home Equity		0		0		0
1-4 family residential		0		0		0
Loans and Leases Receivable, Gross, Consumer, Construction		0		0		0
Bankcard and other revolving plans		0		0		0
Other		0		0		0
Special Mention [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Construction and land development		23		23		52
Term		111		111		82
Loans Receivable, Gross, Commercial, Real Estate		134		134		134
Special Mention [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Commercial and industrial		305		305		266
Leasing		5		5		5
Owner occupied		104		104		96
Municipal		0		0		7
Loans and Leases Receivable before Fees, Gross		414		414		374
Total Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		544		544		567
Total Allowance [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable before Fees, Gross		33		33		31
Total Allowance [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans Receivable, Gross, Commercial, Real Estate		114		114		116
Total Allowance [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable before Fees, Gross		397		397		420
Doubtful [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		1		1		4
Doubtful [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable before Fees, Gross		0		0		0
Loans and Leases Receivable, Gross, Consumer, Home Equity		0		0		0
1-4 family residential		0		0		0
Loans and Leases Receivable, Gross, Consumer, Construction		0		0		0
Bankcard and other revolving plans		0		0		0
Other		0		0		0
Doubtful [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Construction and land development		0		0		0
Term		0		0		0
Loans Receivable, Gross, Commercial, Real Estate		0		0		0
Doubtful [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Commercial and industrial		1		1		3
Leasing		0		0		1
Owner occupied		0		0		0
Municipal		0		0		0
Loans and Leases Receivable before Fees, Gross		1		1		4
Substandard [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		1,463		1,463		1,573
Substandard [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable before Fees, Gross		65		65		64
Loans and Leases Receivable, Gross, Consumer, Home Equity		18		18		16
1-4 family residential		42		42		40
Loans and Leases Receivable, Gross, Consumer, Construction		2		2		4
Bankcard and other revolving plans		2		2		3
Other		1		1		1
Substandard [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Construction and land development		57		57		25
Term		129		129		144
Loans Receivable, Gross, Commercial, Real Estate		186		186		169
Substandard [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Commercial and industrial		887		887		998
Leasing		23		23		30
Owner occupied		296		296		306
Municipal		6		6		6
Loans and Leases Receivable before Fees, Gross		1,212		1,212		1,340
loans held for sale [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		113		113
Loans and Leases Receivable, Gross		128		128
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		15		15
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0		0		0
Financing Receivable, Recorded Investment, Past Due		15		15
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	19		19
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		9,925		9,925		9,638
Loans and Leases Receivable, Gross		9,980		9,980		9,693
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		28		28		22
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		27		27		33
Financing Receivable, Recorded Investment, Past Due		55		55		55
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		4		4		5
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	15		15		17
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		180		180		189
Loans and Leases Receivable, Gross		181		181		190
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		1		1		1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0		0		0
Financing Receivable, Recorded Investment, Past Due		1		1		1
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0		0
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		9,047		9,047		9,291
Loans and Leases Receivable, Gross		9,083		9,083		9,322
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		11		11		9
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		25		25		22
Financing Receivable, Recorded Investment, Past Due		36		36		31
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		14		14		12
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24		24		18
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		2,113		2,113		2,010
Loans and Leases Receivable, Gross		2,123		2,123		2,019
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		3		3		7
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		7		7		2
Financing Receivable, Recorded Investment, Past Due		10		10		9
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0		0		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0		1
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		401		401		423
Loans and Leases Receivable, Gross		404		404		423
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		2		2		0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		1		1		0
Financing Receivable, Recorded Investment, Past Due		3		3		0
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	11		11		14
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		6,880		6,880		6,894
Loans and Leases Receivable, Gross		6,973		6,973		6,962
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		59		59		40
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		34		34		28
Financing Receivable, Recorded Investment, Past Due		93		93		68
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		3		3		8
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	35		35		43
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		811		811		778
Loans and Leases Receivable, Gross		811		811		778
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		0		0		0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0		0		0
Financing Receivable, Recorded Investment, Past Due		0		0		0
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	1		1		1
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		11,160		11,160		11,301
Loans and Leases Receivable, Gross		11,206		11,206		11,341
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		14		14		16
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		32		32		24
Financing Receivable, Recorded Investment, Past Due		46		46		40
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		14		14		13
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24		24		19
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		2,626		2,626		2,635
Loans and Leases Receivable, Gross		2,638		2,638		2,645
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		7		7		4
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		5		5		6
Financing Receivable, Recorded Investment, Past Due		12		12		10
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		2		2		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	4		4		5
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		21,268		21,268		21,401
Loans and Leases Receivable, Gross		21,556		21,556		21,615
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		155		155		112
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		133		133		102
Financing Receivable, Recorded Investment, Past Due		288		288		214
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		12		12		18
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	292		292		345
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		6,156		6,156		5,857
Loans and Leases Receivable, Gross		6,185		6,185		5,891
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		11		11		12
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		18		18		22
Financing Receivable, Recorded Investment, Past Due		29		29		34
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	11		11		11
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		509		509		479
Loans and Leases Receivable, Gross		517		517		486
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		6		6		3
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		2		2		4
Financing Receivable, Recorded Investment, Past Due		8		8		7
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1		1		3
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0		0
Commercial and Industrial Sector [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		13,176		13,176		13,306
Loans and Leases Receivable, Gross		13,368		13,368		13,452
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		94		94		72
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		98		98		74
Financing Receivable, Recorded Investment, Past Due		192		192		146
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		9		9		10
Financing Receivable, Recorded Investment, Nonaccrual Status		358		358		354
Commercial and Industrial Sector [Member] | Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	$ 245		$ 245		$ 287
[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 Credi56

Loans And Allowance For Credit Losses (Summary Of Information On Impaired Loans) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross, Consumer, Home Equity	$ 2,638		$ 2,645
Unpaid principal balance	790		788
Recorded investment	688		660
Impaired Financing Receivable, Related Allowance	50		63
Average recorded investment	655	$ 619
Interest income recognized	6	9
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	126		115
Recorded investment	112		101
Impaired Financing Receivable, Related Allowance	3		3
Average recorded investment	101	122
Interest income recognized	2	2
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	1		1
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	587		586
Recorded investment	520		495
Impaired Financing Receivable, Related Allowance	43		55
Average recorded investment	495	405
Interest income recognized	3	4
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	20		22
Recorded investment	12		13
Impaired Financing Receivable, Related Allowance	0		0
Average recorded investment	13	15
Interest income recognized	0	1
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	98		92
Recorded investment	77		70
Impaired Financing Receivable, Related Allowance	2		2
Average recorded investment	68	106
Interest income recognized	2	3
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	118		114
Recorded investment	89		83
Impaired Financing Receivable, Related Allowance	2		2
Average recorded investment	81	121
Interest income recognized	2	4
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	23		24
Recorded investment	21		23
Impaired Financing Receivable, Related Allowance	0		0
Average recorded investment	21	25
Interest income recognized	0	0
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross, Consumer, Home Equity	2,638		2,645
Unpaid principal balance	2		2
Recorded investment	1		1
Impaired Financing Receivable, Related Allowance	0		0
Average recorded investment	1	2
Interest income recognized	0	0
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	57		59
Recorded investment	54		55
Impaired Financing Receivable, Related Allowance	5		6
Average recorded investment	54	63
Interest income recognized	1	1
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	3		3
Recorded investment	3		3
Impaired Financing Receivable, Related Allowance	0		0
Average recorded investment	3	3
Interest income recognized	0	0
Revolving Credit Facility [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Average recorded investment	0	0
Interest income recognized	0	0
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	85		88
Recorded investment	79		82
Impaired Financing Receivable, Related Allowance	5		6
Average recorded investment	79	93
Interest income recognized	1	1
Impaired Financing Receivable Related Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	411		401
Impaired Financing Receivable Related Allowance [Member] | Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	57		30
Impaired Financing Receivable Related Allowance [Member] | Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	0		0
Impaired Financing Receivable Related Allowance [Member] | Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	342		341
Impaired Financing Receivable Related Allowance [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	10		6
Impaired Financing Receivable Related Allowance [Member] | Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	25		17
Impaired Financing Receivable Related Allowance [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	35		23
Impaired Financing Receivable Related Allowance [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	6		7
Impaired Financing Receivable Related Allowance [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	0		0
Impaired Financing Receivable Related Allowance [Member] | One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	27		28
Impaired Financing Receivable Related Allowance [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	1		2
Impaired Financing Receivable Related Allowance [Member] | Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	34		37
Impaired Financing Receivable Recorded Investment With No Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	277		259
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	55		71
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	1		1
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	178		154
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	2		7
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	52		53
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	54		60
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	15		16
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	1		1
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	27		27
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	2		1
Impaired Financing Receivable Recorded Investment With No Allowance [Member] | Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	45		45
Commercial and Industrial Sector [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Unpaid principal balance	460		470
Recorded investment	407		393
Impaired Financing Receivable, Related Allowance	40		52
Average recorded investment	393	282
Interest income recognized	1	$ 2
Commercial and Industrial Sector [Member] | Impaired Financing Receivable Related Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	285		311
Commercial and Industrial Sector [Member] | Impaired Financing Receivable Recorded Investment With No Allowance [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Recorded investment	$ 122		$ 82

Loans And Allowance For Credi57

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		12 Months Ended
		Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 18	$ 7	$ 129	$ 180
1-4 family residential		6,185		6,185		$ 5,891
Construction and other consumer real estate		517		517		486
Commercial and industrial		13,368		13,368		13,452
Home equity credit line		2,638		2,638		2,645
Bankcard and other revolving plans		459		459		481
Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		14	3
Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	4
Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		16	7
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
Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		6,185		6,185		5,891
Construction and other consumer real estate		517		517		486
Home equity credit line		2,638		2,638		2,645
Bankcard and other revolving plans		459		459		481
Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	4
Recorded investment resulting from the following modification types		167		167		151
Accruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Commercial and industrial		66		66		47
Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	4
Recorded investment resulting from the following modification types		21		21		22
Accruing [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	4
Recorded investment resulting from the following modification types		87		87		69
Accruing [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		5		5		8
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		18		18		17
Accruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Recorded investment resulting from the following modification types		23		23		25
Accruing [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		15		15		14
Accruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		40		40		42
Accruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		2		2		1
Accruing [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		57		57		57
Accruing [Member] | Interest Rate Below Market [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		8		8		10
Accruing [Member] | Interest Rate Below Market [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		1		1		0
Accruing [Member] | Interest Rate Below Market [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		3
Accruing [Member] | Interest Rate Below Market [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2		2		3
Accruing [Member] | Interest Rate Below Market [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Interest Rate Below Market [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		5		5		4
Accruing [Member] | Interest Rate Below Market [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		5		5		4
Accruing [Member] | Interest Rate Below Market [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		0		0		0
Accruing [Member] | Interest Rate Below Market [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		1		1		3
Accruing [Member] | Interest Rate Below Market [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		0		0		0
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		3
Accruing [Member] | Maturity Or Team Extension [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		36		36		25
Accruing [Member] | Maturity Or Team Extension [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		29		29		19
Accruing [Member] | Maturity Or Team Extension [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Maturity Or Team Extension [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		29		29		19
Accruing [Member] | Maturity Or Team Extension [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		3		3		4
Accruing [Member] | Maturity Or Team Extension [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Maturity Or Team Extension [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		3		3		4
Accruing [Member] | Maturity Or Team Extension [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		2		2		1
Accruing [Member] | Maturity Or Team Extension [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		1		1		1
Accruing [Member] | Maturity Or Team Extension [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		1		1		0
Accruing [Member] | Maturity Or Team Extension [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		4		4		2
Accruing [Member] | Principal Forgiveness [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		18		18		17
Accruing [Member] | Principal Forgiveness [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		0		0		0
Accruing [Member] | Principal Forgiveness [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Accruing [Member] | Principal Forgiveness [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Accruing [Member] | Principal Forgiveness [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Principal Forgiveness [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		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		0
Accruing [Member] | Principal Forgiveness [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		10		10		10
Accruing [Member] | Principal Forgiveness [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		7		7		6
Accruing [Member] | Principal Forgiveness [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		0		0		0
Accruing [Member] | Principal Forgiveness [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		17		17		16
Accruing [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Accruing [Member] | Payment Deferral [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		0		0		0
Accruing [Member] | Payment Deferral [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Payment Deferral [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Payment Deferral [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Payment Deferral [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		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		1
Accruing [Member] | Payment Deferral [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		0		0		0
Accruing [Member] | Payment Deferral [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		0		0		0
Accruing [Member] | Payment Deferral [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		0		0		0
Accruing [Member] | Payment Deferral [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	12		12		12
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	[1]	0		0		0
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]	8		8		8
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]	8		8		8
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	0		0		0
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]	2		2		2
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]	2		2		2
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	[1]	0		0		0
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	[1]	2		2		2
Accruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	[1]	0		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]	2		2		2
Accruing [Member] | Multiple Modification Types [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	92		92		86
Accruing [Member] | Multiple Modification Types [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	[2]	36		36		28
Accruing [Member] | Multiple Modification Types [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	11		11		10
Accruing [Member] | Multiple Modification Types [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	47		47		38
Accruing [Member] | Multiple Modification Types [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	2		2		4
Accruing [Member] | Multiple Modification Types [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	10		10		10
Accruing [Member] | Multiple Modification Types [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	12		12		14
Accruing [Member] | Multiple Modification Types [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	[2]	3		3		3
Accruing [Member] | Multiple Modification Types [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	[2]	29		29		30
Accruing [Member] | Multiple Modification Types [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	[2]	1		1		1
Accruing [Member] | Multiple Modification Types [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	33		33		34
Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		18	3
Recorded investment resulting from the following modification types		298		298		251
Nonaccruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		14	3
Commercial and industrial		91		91		60
Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	0
Recorded investment resulting from the following modification types		18		18		17
Nonaccruing [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Nonaccruing [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		16	3
Recorded investment resulting from the following modification types		110		110		78
Nonaccruing [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2		2		2
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		8		8		8
Nonaccruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	$ 0
Recorded investment resulting from the following modification types		10		10		10
Nonaccruing [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		1		1		2
Nonaccruing [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		9		9		8
Nonaccruing [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		1		1		2
Nonaccruing [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		11		11		12
Nonaccruing [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		131		131		100
Nonaccruing [Member] | Interest Rate Below Market [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		15		15		13
Nonaccruing [Member] | Interest Rate Below Market [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		4		4		1
Nonaccruing [Member] | Interest Rate Below Market [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		0
Nonaccruing [Member] | Interest Rate Below Market [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Interest Rate Below Market [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		5		5		1
Nonaccruing [Member] | Interest Rate Below Market [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Interest Rate Below Market [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2		2		2
Nonaccruing [Member] | Interest Rate Below Market [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2		2		2
Nonaccruing [Member] | Interest Rate Below Market [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		0		0		0
Nonaccruing [Member] | Interest Rate Below Market [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		0		0		0
Nonaccruing [Member] | Interest Rate Below Market [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		0		0		0
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		0
Nonaccruing [Member] | Interest Rate Below Market [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		7		7		3
Nonaccruing [Member] | Maturity Or Team Extension [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		41		41		28
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		0		0		0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2		2		1
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		3		3		2
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		1
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		0		0		0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		1		1		0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		0		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		1		1		0
Nonaccruing [Member] | Maturity Or Team Extension [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		5		5		3
Nonaccruing [Member] | Principal Forgiveness [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		35		35		20
Nonaccruing [Member] | Principal Forgiveness [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		14		14		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		14		14		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		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		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		1		1		1
Nonaccruing [Member] | Principal Forgiveness [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		2		2		2
Nonaccruing [Member] | Principal Forgiveness [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		0		0		0
Nonaccruing [Member] | Principal Forgiveness [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		3		3		3
Nonaccruing [Member] | Principal Forgiveness [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		17		17		3
Nonaccruing [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		4		4		7
Nonaccruing [Member] | Payment Deferral [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial		1		1		1
Nonaccruing [Member] | Payment Deferral [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		3
Nonaccruing [Member] | Payment Deferral [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Payment Deferral [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		2		2		4
Nonaccruing [Member] | Payment Deferral [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Payment Deferral [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Payment Deferral [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Payment Deferral [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line		0		0		0
Nonaccruing [Member] | Payment Deferral [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential		0		0		0
Nonaccruing [Member] | Payment Deferral [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate		1		1		2
Nonaccruing [Member] | Payment Deferral [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		1		1		2
Nonaccruing [Member] | Payment Deferral [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		3		3		6
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	72		72		51
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	[1]	53		53		33
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		2		1
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		0		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]	55		55		34
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[1]	2		2		2
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]	2		2		2
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]	4		4		4
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	[1]	0		0		0
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	[1]	1		1		1
Nonaccruing [Member] | Other Recorded Investment Resulting From Following Modification [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	[1]	0		0		0
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		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]	60		60		39
Nonaccruing [Member] | Multiple Modification Types [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	131		131		132
Nonaccruing [Member] | Multiple Modification Types [Member] | Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Commercial and industrial	[2]	19		19		25
Nonaccruing [Member] | Multiple Modification Types [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	12		12		12
Nonaccruing [Member] | Multiple Modification Types [Member] | Municipal [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types		0		0		0
Nonaccruing [Member] | Multiple Modification Types [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	31		31		37
Nonaccruing [Member] | Multiple Modification Types [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	0		0		0
Nonaccruing [Member] | Multiple Modification Types [Member] | Term [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	3		3		3
Nonaccruing [Member] | Multiple Modification Types [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	3		3		3
Nonaccruing [Member] | Multiple Modification Types [Member] | Home Equity Credit Line [Member]
Financing Receivable, Modifications [Line Items]
Home equity credit line	[2]	0		0		1
Nonaccruing [Member] | Multiple Modification Types [Member] | One Through Four Family Residential [Member]
Financing Receivable, Modifications [Line Items]
1-4 family residential	[2]	5		5		5
Nonaccruing [Member] | Multiple Modification Types [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Construction and other consumer real estate	[2]	0		0		0
Nonaccruing [Member] | Multiple Modification Types [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	5		5		6
Nonaccruing [Member] | Multiple Modification Types [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Recorded investment resulting from the following modification types	[2]	$ 39		$ 39		$ 46
[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 Credi58

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		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 18	$ 7	$ 129	$ 180
Loans and Leases Receivable, Gross, Consumer, Home Equity	2,638		2,638		$ 2,645
Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Loans and Leases Receivable, Gross, Consumer, Home Equity	2,638		$ 2,638		$ 2,645
Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	2	4
Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	16	7
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	18	3
Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	2	0
Nonaccruing [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	16	3
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	0
Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	4
Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	4
Accruing [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	4
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	$ 0

Loans And Allowance For Credi59

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		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 18	$ 7	$ 129	$ 180
Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	4
Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	18	3
Commercial And Industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	14	3
Commercial And Industrial [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0
Commercial And Industrial [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	14	3
Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	2	4
Owner Occupied [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	4
Owner Occupied [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	2	0
Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	16	7
Commercial Loan [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	4
Commercial Loan [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	16	3
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
Term [Member] | Nonaccruing [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
Commercial Real Estate [Member] | Accruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	0	0
Commercial Real Estate [Member] | Nonaccruing [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 2	$ 0

Loans And Allowance For Credi60

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, 2017	Dec. 31, 2016
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		$ 389	$ 309
Financing Receivable, Recorded Investment, Current		42,353	42,340
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		197	150
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		192	159
Loans and Leases Receivable, Gross		42,742	42,649
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		30	36
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	331	381
Commercial		44	49
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Commercial Real Estate		47	51
Consumer		8	9
Outstanding balance		99	109
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Carrying Amount, Net		70	77
ALLL		1	1
Carrying amount, net		69	76
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		15
Financing Receivable, Recorded Investment, Current		113
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		0	0
Loans and Leases Receivable, Gross		128
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	19
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		3	0
Financing Receivable, Recorded Investment, Current		401	423
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		2	0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		1	0
Loans and Leases Receivable, Gross		404	423
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	11	14
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		93	68
Financing Receivable, Recorded Investment, Current		6,880	6,894
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		59	40
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		34	28
Loans and Leases Receivable, Gross		6,973	6,962
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		3	8
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	35	43
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		811	778
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	0
Loans and Leases Receivable, Gross		811	778
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	1	1
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		288	214
Financing Receivable, Recorded Investment, Current		21,268	21,401
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		155	112
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		133	102
Loans and Leases Receivable, Gross		21,556	21,615
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		12	18
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	292	345
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		10	9
Financing Receivable, Recorded Investment, Current		2,113	2,010
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		3	7
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		7	2
Loans and Leases Receivable, Gross		2,123	2,019
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0	1
Term [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		36	31
Financing Receivable, Recorded Investment, Current		9,047	9,291
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		11	9
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		25	22
Loans and Leases Receivable, Gross		9,083	9,322
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		14	12
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24	18
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		46	40
Financing Receivable, Recorded Investment, Current		11,160	11,301
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		14	16
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		32	24
Loans and Leases Receivable, Gross		11,206	11,341
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		14	13
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24	19
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		12	10
Financing Receivable, Recorded Investment, Current		2,626	2,635
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		7	4
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		5	6
Loans and Leases Receivable, Gross		2,638	2,645
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		2	1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	4	5
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		29	34
Financing Receivable, Recorded Investment, Current		6,156	5,857
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		11	12
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		18	22
Loans and Leases Receivable, Gross		6,185	5,891
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	11	11
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		8	7
Financing Receivable, Recorded Investment, Current		509	479
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		6	3
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		2	4
Loans and Leases Receivable, Gross		517	486
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1	3
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0	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		5	3
Financing Receivable, Recorded Investment, Current		454	478
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		3	2
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		2	1
Loans and Leases Receivable, Gross		459	481
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1	1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0	1
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		180	189
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		1	1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0	0
Loans and Leases Receivable, Gross		181	190
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0	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		55	55
Financing Receivable, Recorded Investment, Current		9,925	9,638
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		28	22
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		27	33
Loans and Leases Receivable, Gross		9,980	9,693
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		4	5
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	15	17
Commercial and Industrial Sector [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		192	146
Financing Receivable, Recorded Investment, Current		13,176	13,306
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		94	72
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		98	74
Loans and Leases Receivable, Gross		13,368	13,452
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		9	10
Financing Receivable, Recorded Investment, Nonaccrual Status		358	354
Commercial and Industrial Sector [Member] | Commercial And Industrial [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	$ 245	$ 287
[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 Credi61

Loans And Allowance For Credit Losses (Schedule Of Changes In The Accretable Yield For PCI Loans) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Loans And Allowance For Credit Losses [Abstract]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion	$ (4)	$ (6)
Changes in Accretable Yield [Roll Forward]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield	32	43	$ 33	$ 40
Disposals and other	1	1
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Reclassifications from Nonaccretable Difference	$ 2	$ 8

Derivative Instruments And He62

Derivative Instruments And Hedging Activities (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017		Mar. 31, 2016	Dec. 31, 2016
Derivative [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	$ (2)		$ 21
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	2		3
Fair values of derivative assets reduced (increased) by net credit valuation adjustments	2		5
Total derivatives, Notional amount	6,133			$ 6,209
Cash collateral pledged for derivative liabilities	37
Additional collateral that would be required to be pledge if credit rating was downgraded by one notch	1
Derivative Instrument, Noninterest Income (Expense)	4		2
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] | Cash Flow Hedging [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net	(2)		21
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	2	[1]	3
Total derivatives, Notional amount	1,388			1,388
Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivatives, Notional amount	4,745			4,821
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Total derivatives, Notional amount	201			235
Derivative Instrument, Noninterest Income (Expense)	(1)		0
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member]
Derivative [Line Items]
Total derivatives, Notional amount	4,106			4,162
Derivative Instrument, Noninterest Income (Expense)	1		0
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange [Member]
Derivative [Line Items]
Total derivatives, Notional amount	438			424
Derivative Instrument, Noninterest Income (Expense)	4		$ 2
Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	56			59
Other Liabilities [Member] | Derivatives Designated As Hedging Instruments [Member] | Cash Flow Hedging [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	3			1
Other Liabilities [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	53			58
Other Liabilities [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	1			0
Other Liabilities [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	45			49
Other Liabilities [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	7			9
Other Liabilities [Member] | Derivative Financial Instruments, Liabilities [Member]
Derivative [Line Items]
Gross amounts recognized	$ 56			$ 59
[1]	Amounts recognized in OCI and reclassified from AOCI represent the effective portion of the derivative gain (loss).

Derivative Instruments And He63

Derivative Instruments And Hedging Activities (Schedule Of Notional Amounts And Recorded Gross Fair Values And Related Gain (Loss) Of Derivative Instruments) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017		Mar. 31, 2016	Dec. 31, 2016
Derivative [Line Items]
Total derivatives, Notional amount	$ 6,133			$ 6,209
Amount of derivative gain (loss), recognized in OCI	(2)		$ 21
Amount of derivative gain (loss), Reclassified from AOCI to interest income	2		3
Derivatives instruments, Noninterest income (expense)	4		2
Derivatives designated as hedging instruments, Offset to interest expense	0		0
Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	55			64
Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	56			59
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Total derivatives, Notional amount	1,388			1,388
Amount of derivative gain (loss), recognized in OCI	(2)		21
Amount of derivative gain (loss), Reclassified from AOCI to interest income	2	[1]	3
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Assets [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	1			2
Derivatives Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Liabilities [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	3			1
Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Total derivatives, Notional amount	4,745			4,821
Derivatives Not Designated As Hedging Instruments [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	54			62
Derivatives Not Designated As Hedging Instruments [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	53			58
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange [Member]
Derivative [Line Items]
Total derivatives, Notional amount	438			424
Derivatives instruments, Noninterest income (expense)	4		2
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	9			11
Derivatives Not Designated As Hedging Instruments [Member] | Foreign Exchange [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	7			9
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Total derivatives, Notional amount	201			235
Derivatives instruments, Noninterest income (expense)	(1)		0
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	1			2
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	1			0
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member]
Derivative [Line Items]
Total derivatives, Notional amount	4,106			4,162
Derivatives instruments, Noninterest income (expense)	1		$ 0
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member] | Other Assets [Member]
Derivative [Line Items]
Derivatives hedging instruments, assets	44			49
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps For Customers [Member] | Other Liabilities [Member]
Derivative [Line Items]
Derivatives hedging instruments, liabilities	$ 45			$ 49
[1]	Amounts recognized in OCI and reclassified from AOCI represent the effective portion of the derivative gain (loss).

Debt And Shareholders' Equity64

Debt And Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, shares in Thousands	3 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
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, 2016 Subordinated notes $ 247 $ 247 Senior notes 135 287 Capital lease obligations 1 1 Total $ 383 $ 535
Subordinated Debt		$ 247,000,000		$ 247,000,000
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		12,000,000	$ 45,000,000
Stockholders' Equity [Abstract]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		1,000,000	2,000,000
Senior Notes		135,000,000		287,000,000
Capital Lease Obligations		1,000,000		1,000,000
Long-term Debt, Gross		$ 383,000,000		535,000,000
Stock Repurchased During Period, Shares		1,100
Stock Repurchased and Retired During Period, Value		$ 45,000,000
Treasury Stock Acquired, Average Cost Per Share		$ 42.43
Treasury Stock Acquired, Repurchase Authorization		45
Accumulated Other Comprehensive Income (Loss), Net of Tax		$ (111,000,000)	(12,000,000)	$ (122,000,000)	$ (55,000,000)
Repayments of Long-term Debt		153,000,000	$ 11,000,000
Senior Notes [Member]
Stockholders' Equity [Abstract]
Repayments of Long-term Debt		$ 153,000,000
Subsequent Event [Member]
Stockholders' Equity [Abstract]
Preferred Stock, Tender Offer	$ 144,000,000
Dividends, Preferred Stock, Cash	0.49375
Dividends, Preferred Stock, Cash	$ 3,000,000

Debt And Shareholders' Equity65

Debt And Shareholders' Equity (Schedule Of Changes In Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Debt And Shareholders' Equity [Line Items]
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	$ 7	$ 20
Interest income expense, net, after tax	129	79
Income Tax Expense (Benefit)	45	41
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	12	45
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(1)	(2)
Beginning balance	(122)	(55)
Other comprehensive income (loss)	11	43
Ending balance	(111)	(12)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(1)	7
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax	0	1
Other Comprehensive Income (Loss), Tax	6	28
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Debt And Shareholders' Equity [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	12	32
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0
Beginning balance	(93)	(18)
Other comprehensive income (loss)	12	32
Ending balance	(81)	14
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	0	14
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(1)	(2)
Beginning balance	2	1
Other comprehensive income (loss)	(1)	12
Ending balance	1	13
Accumulated Defined Benefit Plans Adjustment [Member]
Debt And Shareholders' Equity [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	(1)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0
Beginning balance	(31)	(38)
Other comprehensive income (loss)	0	(1)
Ending balance	(31)	(39)
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	2	3
Interest income expense, net, after tax	1	2
Income Tax Expense (Benefit)	$ 1	$ 1

Debt And Shareholders' Equity66

Debt And Shareholders' Equity Schedule of Long-Term Debt Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Subordinated Debt	$ 247	$ 247
Senior Notes	135	287
Capital Lease Obligations	1	1
Long-term Debt, Gross	$ 383	$ 535

Commitments, Guarantees, And 67

Commitments, Guarantees, And Contingent Liabilities (Narrative) (Details) $ in Millions	Mar. 31, 2017USD ($)
Guarantor Obligations [Line Items]
Letters of credit, accrued liability	$ 5
Reserve for unfunded lending commitments	2
Deferred commitment fees	3
Commitments for Private Equity and Other Noninterest-bearing Investments	24
Commitments for Private Equity or Other Non-Interest Bearing Investments Prohibited by the Volcker Rule	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	$ 20

Commitments, Guarantees, And 68

Commitments, Guarantees, And Contingent Liabilities (Schedule Of Guarantees Issued) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Unused Commitments to Extend Credit	$ 18,467	$ 18,274
Commercial Letters Of Credit	77	60
Total Unfunded Lending Commitments	19,436	19,301
Financial [Member]
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Standby letters of credit	701	771
Performance [Member]
Liabilities for Guarantees on Long-Duration Contracts [Line Items]
Standby letters of credit	191	$ 196
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	$ 20

Retirement Plans (Schedule Of N

Retirement Plans (Schedule Of Net Periodic Benefit Cost (Credit) For Pension And Postretirement Plans) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 2	$ 2
Expected return on plan assets	(3)	(3)
Amortization of net actuarial (gain) loss	1	2
Net periodic benefit cost (credit)	1	1
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	$ 1	$ 0

Retirement Plans Retirement Pla

Retirement Plans Retirement Plans (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements	$ (1)	$ 0

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, Percent	24.50%	31.10%
Current State and Local Tax Expense (Benefit)	$ 14
Income Tax Effects Allocated Directly to Equity, Cumulative Effect of Change in Accounting Principle	4
Deferred Tax Assets, Net	$ 231		$ 250
Operating Loss Carryforwards, Valuation Allowance			$ 4

Operating Segment Information72

Operating Segment Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)Branches	Mar. 31, 2016USD ($)
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	$ 489	$ 453
Provision for Loan and Lease Losses	23	42
Interest Income (Expense), after Provision for Loan Loss	466	411
Noninterest Income, Other Operating Income	0	0
Noninterest Expense	414	396
Income (Loss) from Continuing Operations before Income Taxes, Domestic	184	132
Zions Bank [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	155	150
Provision for Loan and Lease Losses	35	(31)
Interest Income (Expense), after Provision for Loan Loss	120	181
Noninterest Income, Other Operating Income	35	36
Noninterest Expense	113	105
Income (Loss) from Continuing Operations before Income Taxes, Domestic	42	112
Average Loans And Leases	12,488	12,306
Average Deposits	16,268	15,700
Amegy [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	114	113
Provision for Loan and Lease Losses	1	104
Interest Income (Expense), after Provision for Loan Loss	113	9
Noninterest Income, Other Operating Income	29	29
Noninterest Expense	85	86
Income (Loss) from Continuing Operations before Income Taxes, Domestic	57	(48)
Average Loans And Leases	10,637	10,370
Average Deposits	$ 11,318	11,274
Number of Branches | Branches	74
California Bank Trust [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	$ 110	103
Provision for Loan and Lease Losses	(5)	(3)
Interest Income (Expense), after Provision for Loan Loss	115	106
Noninterest Income, Other Operating Income	17	16
Noninterest Expense	75	72
Income (Loss) from Continuing Operations before Income Taxes, Domestic	57	50
Average Loans And Leases	9,306	8,905
Average Deposits	$ 10,921	10,479
Number of Branches | Branches	93
NBA [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	$ 50	45
Provision for Loan and Lease Losses	1	2
Interest Income (Expense), after Provision for Loan Loss	49	43
Noninterest Income, Other Operating Income	9	10
Noninterest Expense	37	35
Income (Loss) from Continuing Operations before Income Taxes, Domestic	21	18
Average Loans And Leases	4,262	3,863
Average Deposits	$ 4,661	4,445
Number of Branches | Branches	58
Nevada State Bank [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	$ 32	30
Provision for Loan and Lease Losses	(4)	(26)
Interest Income (Expense), after Provision for Loan Loss	36	56
Noninterest Income, Other Operating Income	10	9
Noninterest Expense	35	33
Income (Loss) from Continuing Operations before Income Taxes, Domestic	11	32
Average Loans And Leases	2,338	2,263
Average Deposits	$ 4,211	4,011
Number of Branches | Branches	50
Vectra Bank Colorado [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	$ 30	30
Provision for Loan and Lease Losses	(3)	(3)
Interest Income (Expense), after Provision for Loan Loss	33	33
Noninterest Income, Other Operating Income	6	6
Noninterest Expense	25	23
Income (Loss) from Continuing Operations before Income Taxes, Domestic	14	16
Average Loans And Leases	2,535	2,453
Average Deposits	2,791	2,783
TCBW [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	11	9
Provision for Loan and Lease Losses	(1)	(2)
Interest Income (Expense), after Provision for Loan Loss	12	11
Noninterest Income, Other Operating Income	1	1
Noninterest Expense	5	5
Income (Loss) from Continuing Operations before Income Taxes, Domestic	8	7
Average Loans And Leases	877	733
Average Deposits	1,100	953
Other Segment [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	(13)	(27)
Provision for Loan and Lease Losses	(1)	1
Interest Income (Expense), after Provision for Loan Loss	(12)	(28)
Noninterest Income, Other Operating Income	25	10
Noninterest Expense	39	37
Income (Loss) from Continuing Operations before Income Taxes, Domestic	(26)	(55)
Average Loans And Leases	123	110
Average Deposits	$ 942	(90)
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 | TCBW [Member]
Segment Reporting Information [Line Items]
Number of Branches | Branches	1
OREGON | TCBW [Member]
Segment Reporting Information [Line Items]
Number of Branches | Branches	1
Consolidated Entities [Member]
Segment Reporting Information [Line Items]
Interest Income (Expense), Net	$ 489	453
Provision for Loan and Lease Losses	23	42
Interest Income (Expense), after Provision for Loan Loss	466	411
Noninterest Income, Other Operating Income	132	117
Noninterest Expense	414	396
Income (Loss) from Continuing Operations before Income Taxes, Domestic	184	132
Average Loans And Leases	42,566	41,003
Average Deposits	$ 52,212	$ 49,555