XML 66 R56.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Stockholders' Equity - Summary of Shares Repurchased Under Stock Purchase Program (Detail) - shares | Sep. 30, 2018 | Sep. 30, 2017
--- | --- | ---
Summary Of Shares Repurchased Under Stock Purchase Program [Abstract] |  |
Shares remaining to be repurchased | 300,000 | 300,000

X
- Definition Summary of shares repurchased under stock purchase program. + References No definition available. + Details
Name: | banf_SummaryOfSharesRepurchasedUnderStockPurchaseProgramAbstract
Namespace Prefix: | banf_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The remaining number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan. + References No definition available. + Details
Name: | us-gaap_StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant