Basis of Presentaion

3 Months Ended

Mar. 31, 2016

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 endedMarch 31, 2016 and 2015 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, 2015 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 2015 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 is a financial holding company headquartered in Salt Lake City, Utah, and with its subsidiaries, provides a full range of banking and related services. Following the close of business on December 31, 2015, the Company completed the merger of its subsidiary banks and other subsidiaries into a single bank, ZB, N.A. The Company continues to manage its banking operations through seven separately managed and branded segments in 11 Western and Southwestern states as follows: Zions Bank, in Utah, Idaho and Wyoming; Amegy Bank (“Amegy”), in Texas; California Bank & Trust (“CB&T”); National Bank of Arizona (“NBAZ”); Nevada State Bank (“NSB”); Vectra Bank Colorado (“Vectra”), in Colorado and New Mexico; and The Commerce Bank of Washington (“TCBW”), in Washington and Oregon. Pursuant to a Board resolution adopted November 21, 2014, The Commerce Bank of Oregon merged into TCBW following the close of business on March 31, 2015.