XML 86 R77.htm IDEA: XBRL DOCUMENT
v3.23.2

Derivative Financial Instruments - Summary of Company's Net Credit Exposure Relating to Oil and Gas Swaps and Options with Bank Counterparties (Detail) - USD ($) $ in Thousands | Jun. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Oil and Natural Gas Swaps and Options [Member] |  |
Credit Derivatives [Line Items] |  |
Credit exposure | $ 21,093 | $ 6,560

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_CreditDerivativesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of credit risk derivative asset after deduction of credit risk derivative liability. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4K -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5708775-113959 + Details
Name: | us-gaap_CreditRiskDerivativesAtFairValueNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=banf_OilAndNaturalGasSwapsAndOptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |