XML 121 R108.htm IDEA: XBRL DOCUMENT
v3.20.4

Net Income Per Common Share - Average Exercise Prices of Options Excluded from Computation of Diluted Net Income Per Common Share (Detail) - $ / shares | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Abstract] |  |  |
Shares | 402,575 | 180,989 | 92,738
Average Exercise Price | $ 52.72 | $ 54.73 | $ 53.17

X
- Definition Average exercise prices of options excluded from computation of diluted net income per common share. + References No definition available. + Details
Name: | banf_AverageExercisePricesOfOptionsExcludedFromComputationOfDilutedNetIncomePerCommonShare
Namespace Prefix: | banf_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule of antidilutive securities excluded from computation of earnings per share. + References No definition available. + Details
Name: | banf_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAbstract
Namespace Prefix: | banf_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 + Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration