XML 20 R121.htm IDEA: XBRL DOCUMENT v2.4.1.9
Segment Information - Results of Operations and Selected Financial Information (Detail) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Segment Reporting Information [Line Items]                      
Net interest income (expense) $ 47,319us-gaap_InterestIncomeExpenseNet $ 46,514us-gaap_InterestIncomeExpenseNet $ 45,489us-gaap_InterestIncomeExpenseNet $ 42,029us-gaap_InterestIncomeExpenseNet $ 41,921us-gaap_InterestIncomeExpenseNet $ 40,712us-gaap_InterestIncomeExpenseNet $ 40,630us-gaap_InterestIncomeExpenseNet $ 40,256us-gaap_InterestIncomeExpenseNet $ 181,351us-gaap_InterestIncomeExpenseNet $ 163,519us-gaap_InterestIncomeExpenseNet $ 164,815us-gaap_InterestIncomeExpenseNet
Provision for loan losses 1,840us-gaap_ProvisionForLoanAndLeaseLosses (3,115)us-gaap_ProvisionForLoanAndLeaseLosses 3,129us-gaap_ProvisionForLoanAndLeaseLosses 1,218us-gaap_ProvisionForLoanAndLeaseLosses 454us-gaap_ProvisionForLoanAndLeaseLosses (12)us-gaap_ProvisionForLoanAndLeaseLosses 516us-gaap_ProvisionForLoanAndLeaseLosses 300us-gaap_ProvisionForLoanAndLeaseLosses 3,072us-gaap_ProvisionForLoanAndLeaseLosses 1,258us-gaap_ProvisionForLoanAndLeaseLosses 3,100us-gaap_ProvisionForLoanAndLeaseLosses
Noninterest income 24,302us-gaap_NoninterestIncome 24,938us-gaap_NoninterestIncome 23,611us-gaap_NoninterestIncome 23,562us-gaap_NoninterestIncome 22,235us-gaap_NoninterestIncome 23,652us-gaap_NoninterestIncome 21,733us-gaap_NoninterestIncome 22,535us-gaap_NoninterestIncome 96,413us-gaap_NoninterestIncome 90,155us-gaap_NoninterestIncome 87,717us-gaap_NoninterestIncome
Depreciation and amortization                 11,349us-gaap_DepreciationDepletionAndAmortization 11,077us-gaap_DepreciationDepletionAndAmortization 10,840us-gaap_DepreciationDepletionAndAmortization
Other expenses                 172,172banf_NoninterestExpenseExcludingDepreciationAndAmortization 160,497banf_NoninterestExpenseExcludingDepreciationAndAmortization 159,588banf_NoninterestExpenseExcludingDepreciationAndAmortization
Income before taxes                 91,171us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments 80,842us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments 79,004us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
Total assets 6,574,972us-gaap_Assets       6,038,974us-gaap_Assets       6,574,972us-gaap_Assets 6,038,974us-gaap_Assets 6,022,250us-gaap_Assets
Capital expenditures                 11,490us-gaap_PaymentsToAcquirePropertyPlantAndEquipment 13,896us-gaap_PaymentsToAcquirePropertyPlantAndEquipment 13,438us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
Operating Segments [Member] | Metropolitan Banks [Member]                      
Segment Reporting Information [Line Items]                      
Net interest income (expense)                 59,923us-gaap_InterestIncomeExpenseNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
56,346us-gaap_InterestIncomeExpenseNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
54,062us-gaap_InterestIncomeExpenseNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
Provision for loan losses                 3,077us-gaap_ProvisionForLoanAndLeaseLosses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
(154)us-gaap_ProvisionForLoanAndLeaseLosses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
1,202us-gaap_ProvisionForLoanAndLeaseLosses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
Noninterest income                 13,752us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
12,881us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
11,222us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
Depreciation and amortization                 2,216us-gaap_DepreciationDepletionAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
2,178us-gaap_DepreciationDepletionAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
1,956us-gaap_DepreciationDepletionAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
Other expenses                 32,300banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
31,396banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
29,511banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
Income before taxes                 36,082us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
35,807us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
32,615us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
Total assets 2,298,828us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
      2,079,444us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
      2,298,828us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
2,079,444us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
1,996,539us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
Capital expenditures                 1,948us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
5,534us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
4,099us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_MetropolitanBanksMember
Operating Segments [Member] | Community Banks [Member]                      
Segment Reporting Information [Line Items]                      
Net interest income (expense)                 116,935us-gaap_InterestIncomeExpenseNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
102,705us-gaap_InterestIncomeExpenseNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
105,966us-gaap_InterestIncomeExpenseNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
Provision for loan losses                 (488)us-gaap_ProvisionForLoanAndLeaseLosses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
1,205us-gaap_ProvisionForLoanAndLeaseLosses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
1,607us-gaap_ProvisionForLoanAndLeaseLosses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
Noninterest income                 51,415us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
48,418us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
43,809us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
Depreciation and amortization                 7,277us-gaap_DepreciationDepletionAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
7,011us-gaap_DepreciationDepletionAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
6,898us-gaap_DepreciationDepletionAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
Other expenses                 89,888banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
84,011banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
80,535banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
Income before taxes                 71,673us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
58,896us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
60,735us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
Total assets 4,113,783us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
      3,764,429us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
      4,113,783us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
3,764,429us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
3,801,653us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
Capital expenditures                 7,972us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
6,445us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
8,045us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_CommunityBanksMember
Operating Segments [Member] | Other Financial Services [Member]                      
Segment Reporting Information [Line Items]                      
Net interest income (expense)                 6,155us-gaap_InterestIncomeExpenseNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
6,239us-gaap_InterestIncomeExpenseNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
7,055us-gaap_InterestIncomeExpenseNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
Provision for loan losses                 481us-gaap_ProvisionForLoanAndLeaseLosses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
121us-gaap_ProvisionForLoanAndLeaseLosses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
182us-gaap_ProvisionForLoanAndLeaseLosses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
Noninterest income                 28,079us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
25,659us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
29,624us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
Depreciation and amortization                 522us-gaap_DepreciationDepletionAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
521us-gaap_DepreciationDepletionAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
485us-gaap_DepreciationDepletionAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
Other expenses                 22,304banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
21,604banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
22,056banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
Income before taxes                 10,927us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
9,652us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
13,956us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
Total assets 145,814us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
      103,656us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
      145,814us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
103,656us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
186,473us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
Capital expenditures                 121us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
219us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
398us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= us-gaap_AllOtherSegmentsMember
Operating Segments [Member] | Executive, Operations & Support [Member]                      
Segment Reporting Information [Line Items]                      
Net interest income (expense)                 (1,662)us-gaap_InterestIncomeExpenseNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
(1,771)us-gaap_InterestIncomeExpenseNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
(2,268)us-gaap_InterestIncomeExpenseNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
Provision for loan losses                 2us-gaap_ProvisionForLoanAndLeaseLosses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
86us-gaap_ProvisionForLoanAndLeaseLosses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
109us-gaap_ProvisionForLoanAndLeaseLosses
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
Noninterest income                 69,442us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
59,298us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
56,848us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
Depreciation and amortization                 1,334us-gaap_DepreciationDepletionAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
1,367us-gaap_DepreciationDepletionAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
1,501us-gaap_DepreciationDepletionAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
Other expenses                 27,998banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
23,818banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
27,783banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
Income before taxes                 38,446us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
32,256us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
25,187us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
Total assets 679,194us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
      703,294us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
      679,194us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
703,294us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
602,342us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
Capital expenditures                 1,449us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
1,698us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
896us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember
/ us-gaap_StatementBusinessSegmentsAxis
= banf_ExecutiveOperationsAndSupportMember
Eliminations [Member]                      
Segment Reporting Information [Line Items]                      
Noninterest income                 (66,275)us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember
(56,101)us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember
(53,786)us-gaap_NoninterestIncome
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember
Other expenses                 (318)banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember
(332)banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember
(297)banf_NoninterestExpenseExcludingDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember
Income before taxes                 (65,957)us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember
(55,769)us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember
(53,489)us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember
Total assets $ (662,647)us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember
      $ (611,849)us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember
      $ (662,647)us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember
$ (611,849)us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember
$ (564,757)us-gaap_Assets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember