XML 47 R52.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail) | 12 Months Ended
--- | ---
Dec. 31, 2014
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] |
Days from origination after which mortgage loan are sold | 30 days
Loan upon which a default of principal or interest has existed for a period | 90 days
Intangible assets, Estimated useful lives | 6 years 6 months
Core Deposit Intangibles [Member] |
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] |
Intangible assets, Estimated useful lives | 5 years 10 months 24 days
Minimum [Member] | Core Deposit Intangibles [Member] |
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] |
Intangible assets, Estimated useful lives | 7 years
Minimum [Member] | Customer Relationship Intangibles [Member] |
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] |
Intangible assets, Estimated useful lives | 3 years
Maximum [Member] | Core Deposit Intangibles [Member] |
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] |
Intangible assets, Estimated useful lives | 10 years
Maximum [Member] | Customer Relationship Intangibles [Member] |
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] |
Intangible assets, Estimated useful lives | 18 years
First Liens [Member] | Minimum [Member] |
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] |
Loans and finance receivables portfolio percentage | 80.00%banf_LoansAndFinanceReceivablesPortfolioPercentage / us-gaap_DebtSecurityAxis = banf_FirstLienMember / us-gaap_RangeAxis = us-gaap_MinimumMember
Junior Liens [Member] | Maximum [Member] |
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] |
Loans and finance receivables portfolio percentage | 15.00%banf_LoansAndFinanceReceivablesPortfolioPercentage / us-gaap_DebtSecurityAxis = banf_JuniorLienMember / us-gaap_RangeAxis = us-gaap_MaximumMember
Home Equity Lines of Credit [Member] | Maximum [Member] |
Basis Of Presentation And Summary Of Significant Accounting Policies [Line Items] |
Loans and finance receivables portfolio percentage | 5.00%banf_LoansAndFinanceReceivablesPortfolioPercentage / us-gaap_DebtSecurityAxis = banf_HomeEquityLineOfCreditMember / us-gaap_RangeAxis = us-gaap_MaximumMember

X
- Details
Name: | banf_BasisOfPresentationAndSummaryOfSignificantAccountingPoliciesLineItems
Namespace Prefix: | banf_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Loans and finance receivables portfolio percentage. + References No definition available. + Details
Name: | banf_LoansAndFinanceReceivablesPortfolioPercentage
Namespace Prefix: | banf_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Period for sale of mortgage loan from origination. + References No definition available. + Details
Name: | banf_PeriodForSaleOfMortgageLoanFromOrigination
Namespace Prefix: | banf_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period of default of principal or interest upon loan. + References No definition available. + Details
Name: | banf_PeriodOfDefaultOfPrincipalOrInterestUponLoan
Namespace Prefix: | banf_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DebtSecurityAxis=banf_FirstLienMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtSecurityAxis=banf_HomeEquityLineOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtSecurityAxis=banf_JuniorLienMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_CoreDepositsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |