XML 24 R55.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Cash Due from Banks Interest-Bearing Deposits and Federal Funds Sold - Summary of Average Amount of Required Reserves (Detail) (USD $) In Thousands, unless otherwise specified | Dec. 31, 2013 | Dec. 31, 2012
--- | --- | ---
Average Amount Of Required Reserves [Abstract] |  |
Vault cash and excess funds with the Federal Reserve Bank | $ 1,758,908 | $ 1,809,584
Average required reserves | $ 37,456 | $ 38,949

X
- Details
Name: | banf_AverageAmountOfRequiredReservesAbstract
Namespace Prefix: | banf_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Vault Cash And Funds In Bank + References No definition available. + Details
Name: | banf_VaultCashAndFundsInBank
Namespace Prefix: | banf_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Vault Cash Equivalents Reserves + References No definition available. + Details
Name: | banf_VaultCashEquivalentsReserves
Namespace Prefix: | banf_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant