Significant Accounting Policies	9 Months Ended
Sep. 30, 2013
Accounting Policies [Abstract]
Significant Accounting Policies	(1) Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed consolidated financial statements of BOK Financial Corporation (“BOK Financial” or “the Company”) have been prepared in accordance with accounting principles for interim financial information generally accepted in the United States 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 generally accepted accounting principles 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. The unaudited consolidated financial statements include accounts of BOK Financial and its subsidiaries, principally BOKF, NA (“the Bank”), BOSC, Inc., The Milestone Group, Inc. and Cavanal Hill Investment Management Inc. Operating divisions of the Bank include Bank of Albuquerque, Bank of Arizona, Bank of Arkansas, Bank of Oklahoma, Bank of Texas, Colorado State Bank and Trust, Bank of Kansas City, BOK Financial Mortgage and the TransFund electronic funds network. Certain reclassifications have been made to conform to the current period presentation. The financial information should be read in conjunction with BOK Financial’s 2012 Form 10-K filed with the Securities and Exchange Commission, which contains audited financial statements. Amounts presented as of December 31, 2012 have been derived from the audited financial statements included in BOK Financial’s 2012 Form 10-K but does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. Operating results for the three-month and nine-month periods ended September 30, 2013 are not necessarily indicative of the results that may be expected for the year ending December 31, 2013. Newly Adopted and Pending Accounting Policies Financial Accounting Standards Board (“FASB”) FASB Accounting Standards Update No. 2011-11, Disclosures about Offsetting Assets and Liabilities (“ASU 2011-11”) On December 16, 2011, the FASB issued ASU 2011-11 which contains new disclosure requirements regarding the nature of an entity's right of setoff and related arrangements associated with its financial instruments and derivative instruments. The new disclosures are anticipated to facilitate comparison between financial statements prepared under generally accepted accounting principles in the United States of America and financial statements prepared under International Financial Reporting Standards by providing information about gross and net exposures. The new disclosure requirements were effective for the Company for interim and annual reporting period beginning January 1, 2013. FASB Accounting Standards Update No. 2013-01, Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities (ASU 2013-01) On January 31, 2013, FASB issued ASU 2013-01 which clarified the scope of ASU 2011-11 applied for derivative contracts accounted for in accordance with Topic 815, Derivatives and Hedging, including bifurcated embedded derivatives, repurchase agreements and reverse repurchase agreements and securities borrowing and lending transactions that are either offset in accordance with Section 210-20-45 or Section 815-10-45 or subject to an enforceable master netting arrangement or similar agreement. ASU 2013-01 was effective for the Company on January 1, 2013. FASB Accounting Standards Update No. 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income ("ASU 2013-02") On February 7, 2013 the FASB issued ASU 2013-02 which sets the requirements for presentation of significant reclassifications out of accumulated other comprehensive income for both items reclassified in their entirety and the respective line items in Statement of Earnings they are being reclassified into and for other amounts that are not reclassified in their entirety to net income during the reporting period, such as items being reclassified to balance sheet accounts. ASU 2013-02 was effective for the Company on January 1, 2013 and is to be applied prospectively.

(1) Significant Accounting Policies

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements of BOK Financial Corporation (“BOK Financial” or “the Company”) have been prepared in accordance with accounting principles for interim financial information generally accepted in the United States 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 generally accepted accounting principles 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.

The unaudited consolidated financial statements include accounts of BOK Financial and its subsidiaries, principally BOKF, NA (“the Bank”), BOSC, Inc., The Milestone Group, Inc. and Cavanal Hill Investment Management Inc. Operating divisions of the Bank include Bank of Albuquerque, Bank of Arizona, Bank of Arkansas, Bank of Oklahoma, Bank of Texas, Colorado State Bank and Trust, Bank of Kansas City, BOK Financial Mortgage and the TransFund electronic funds network.

Certain reclassifications have been made to conform to the current period presentation.

The financial information should be read in conjunction with BOK Financial’s 2012 Form 10-K filed with the Securities and Exchange Commission, which contains audited financial statements. Amounts presented as of December 31, 2012 have been derived from the audited financial statements included in BOK Financial’s 2012 Form 10-K but does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. Operating results for the three-month and nine-month periods ended September 30, 2013 are not necessarily indicative of the results that may be expected for the year ending December 31, 2013.

Newly Adopted and Pending Accounting Policies

Financial Accounting Standards Board (“FASB”)

FASB Accounting Standards Update No. 2011-11, Disclosures about Offsetting Assets and Liabilities (“ASU 2011-11”)

On December 16, 2011, the FASB issued ASU 2011-11 which contains new disclosure requirements regarding the nature of an entity's right of setoff and related arrangements associated with its financial instruments and derivative instruments. The new disclosures are anticipated to facilitate comparison between financial statements prepared under generally accepted accounting principles in the United States of America and financial statements prepared under International Financial Reporting Standards by providing information about gross and net exposures. The new disclosure requirements were effective for the Company for interim and annual reporting period beginning January 1, 2013.

FASB Accounting Standards Update No. 2013-01, Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities (ASU 2013-01)

On January 31, 2013, FASB issued ASU 2013-01 which clarified the scope of ASU 2011-11 applied for derivative contracts accounted for in accordance with Topic 815, Derivatives and Hedging, including bifurcated embedded derivatives, repurchase agreements and reverse repurchase agreements and securities borrowing and lending transactions that are either offset in accordance with Section 210-20-45 or Section 815-10-45 or subject to an enforceable master netting arrangement or similar agreement. ASU 2013-01 was effective for the Company on January 1, 2013.

FASB Accounting Standards Update No. 2013-02, Reporting of Amounts Reclassified Out of Accumulated Other Comprehensive Income ("ASU 2013-02")

On February 7, 2013 the FASB issued ASU 2013-02 which sets the requirements for presentation of significant reclassifications out of accumulated other comprehensive income for both items reclassified in their entirety and the respective line items in Statement of Earnings they are being reclassified into and for other amounts that are not reclassified in their entirety to net income during the reporting period, such as items being reclassified to balance sheet accounts. ASU 2013-02 was effective for the Company on January 1, 2013 and is to be applied prospectively.