Name:	bokf_DecreaseInFairValueOfMortgageServicingRightsDueTo50BasisPointDecreaseInMortgageInterestRates
Namespace Prefix:	bokf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The economic hedge threshold utilized in financial model to estimate interest rate sensitivity in determining fair value of mortgage servicing rights.

No definition available.

Name:	bokf_EconomicHedgeThresholdForInterestRateSensitivityForMortgageServicingRightsAndSecuritiesHeld
Namespace Prefix:	bokf_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The dollar amount of increase in the estimated fair value of mortgage servicing rights as a result of a 50 basis point (.5%) increase in prevailing mortgage interest rates.

No definition available.

Name:	bokf_IncreaseInFairValueOfMortgageServicingRightsDueTo50BasisPointIncreaseInMortgageInterestRates
Namespace Prefix:	bokf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The dollar amount of principal for mortgage loans being serviced for others.

No definition available.

Name:	bokf_LoansServicedForOthers
Namespace Prefix:	bokf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	bokf_StratificationOfMortgageLoanServicingPortfolioLineItems
Namespace Prefix:	bokf_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Annual prepayment estimates based on loan interest rate , original term and loan type.

No definition available.

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

Fair value as of the balance sheet date of an asset representing net future revenues from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS140-4/FIN46(R)-8

-Paragraph B9

-Subparagraph a(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 140

-Paragraph 13A, 13B

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 860

-SubTopic 50

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=7882072&loc=d3e122625-111746

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 140

-Paragraph 17

-Subparagraph f(1)(a)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.