XML 79 R69.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Subsequent Event - Additonal Information (Details) - Scenario, Forecast [Member] $ in Millions | Aug. 15, 2018 USD ($)
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Subsequent Event [Line Items] |
Non-binding contract price subject to court approval | $ 21.0
Expected date to be announced on non-binding contract price subject to court approval | Aug. 15, 2018

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- Definition Expected date to be announced on non-binding contract price subject to court approval. + References No definition available. + Details
Name: | banf_ExpectedDateToBeAnnouncedOnNonBindingContractPriceSubjectToCourtApproval
Namespace Prefix: | banf_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

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- Definition Non-binding contract price subject to court approval. + References No definition available. + Details
Name: | banf_NonBindingContractPriceSubjectToCourtApproval
Namespace Prefix: | banf_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Definition Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. + References No definition available. + Details
Name: | us-gaap_SubsequentEventLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |