Significant Accounting Policies Newly Adopted and Pending Accounting Pronouncements (Details)	6 Months Ended
Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Percentage of gross revenue of Transaction Card Revenue and Fiduciary and Asset Management Revenue	19.00%
Percentage of fees and commission revenue composed of Transaction Card Revenue and Fiduciary and Asset Management Revenue	43.00%

Represents percentage of fees and commissions revenue composed of Transaction Card Revenue and Fiduciary and Asset Management Revenue in consideration of the impact of FASB Accounting Standards Updated No. 2014-09 "Revenue from Contracts with Customers"

No definition available.

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Namespace Prefix:	bokf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration