Acquisitions	6 Months Ended
Jun. 30, 2016
Acquisitions [Abstract]
Business Combination Disclosure [Text Block]	(5) Acquisitions On December 8, 2015, the Company announced the signing of a definitive purchase agreement with MBT Bancshares (“MBT”). MBT is headquartered in Kansas City, Mo. and is the parent company of Missouri Bank and Trust of Kansas City (“mobank”). mobank operates four banking branches in the Kansas City, Mo. area. Under terms of the definitive agreement, BOK Financial will pay $102.5 million in an all-cash deal for all outstanding shares of MBT stock, subject to certain conditions and potential adjustments. The transaction has been approved by the boards of directors of both companies and is expected to close by the end of 2016, subject to customary closing conditions, including regulatory approval. In the first quarter of 2016, the Company acquired Weaver and Tidwell Financial Advisors LTD d/b/a Weaver Wealth Management, a registered investment advisor and E-Spectrum Advisors, an energy investment banking firm in Texas. The cash purchase price for these acquisitions was $7.7 million. The purchase price allocation included $5.3 million of identifiable intangible assets and $3.3 million of goodwill. On May 4, 2015, the Company acquired a majority voting interest in Heartland Food Products, LLC, a Kansas-based food product and restaurant equipment company. The cash purchase price for this acquisition was $18 million. The final purchase price allocation included $11 million of identifiable intangible assets and $2.7 million of goodwill. The pro-forma impact of these transactions was not material to the Company's consolidated financial statements.

Acquisitions

6 Months Ended

Jun. 30, 2016

Business Combination Disclosure [Text Block]

(5) Acquisitions

On December 8, 2015, the Company announced the signing of a definitive purchase agreement with MBT Bancshares (“MBT”). MBT is headquartered in Kansas City, Mo. and is the parent company of Missouri Bank and Trust of Kansas City (“mobank”). mobank operates four banking branches in the Kansas City, Mo. area. Under terms of the definitive agreement, BOK Financial will pay $102.5 million in an all-cash deal for all outstanding shares of MBT stock, subject to certain conditions and potential adjustments. The transaction has been approved by the boards of directors of both companies and is expected to close by the end of 2016, subject to customary closing conditions, including regulatory approval.

In the first quarter of 2016, the Company acquired Weaver and Tidwell Financial Advisors LTD d/b/a Weaver Wealth Management, a registered investment advisor and E-Spectrum Advisors, an energy investment banking firm in Texas. The cash purchase price for these acquisitions was $7.7 million. The purchase price allocation included $5.3 million of identifiable intangible assets and $3.3 million of goodwill.

On May 4, 2015, the Company acquired a majority voting interest in Heartland Food Products, LLC, a Kansas-based food product and restaurant equipment company. The cash purchase price for this acquisition was $18 million. The final purchase price allocation included $11 million of identifiable intangible assets and $2.7 million of goodwill.

The pro-forma impact of these transactions was not material to the Company's consolidated financial statements.