XML 107 R94.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Stock-Based Compensation - Unearned Stock-based Compensation Expense (Detail) $ in Thousands | Dec. 31, 2017 USD ($)
--- | ---
Remaining Fair Value Of Stock Options [Abstract] |
Unearned stock-based compensation expense | $ 3,268

X
- Definition Remaining fair value of stock options. + References No definition available. + Details
Name: | banf_RemainingFairValueOfStockOptionsAbstract
Namespace Prefix: | banf_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Unrecognized cost of unvested share-based compensation awards. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant