Stockholders' Equity - Required Capital Amounts and Company's Respective Ratios (Detail) $ in Thousands	Sep. 30, 2024 USD ($)
Parent Company [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 1,599,885
Total Capital To Risk Weighted Assets Actual Ratio	0.1753
Capital Required For Capital Adequacy Amount	$ 729,952
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	0.08
Capital With Capital Conservation Buffer Amount	$ 958,062
Capital With Capital Conservation To Risk Based Weighted Assets Buffer Ratio	0.105
Common Equity Tier 1 Risk Based Capital Amount	$ 1,412,664
Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.1548
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 410,598
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	0.045
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer Amount	$ 638,708
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	0.07
Tier 1 Risk Based Capital Amount	$ 1,438,664
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.1577
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 547,464
Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	0.06
Tier 1 Risk Based Capital With Capital Conservation Buffer Amount	$ 775,574
Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	0.085
Tier 1 Capital Amount	$ 1,438,664
Tier 1 Capital To Quarterly Average Assets Ratio	0.1119
Tier 1 Capital Required For Capital Adequacy Amount	$ 514,059
Tier 1 Capital Required For Capital Adequacy To Quarterly Average Assets Ratio	0.04
BancFirst [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 1,232,839
Total Capital To Risk Weighted Assets Actual Ratio	0.1612
Capital Required For Capital Adequacy Amount	$ 611,761
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	0.08
Capital With Capital Conservation Buffer Amount	$ 802,936
Capital With Capital Conservation To Risk Based Weighted Assets Buffer Ratio	0.105
Capital Required To Be Well Capitalized Amount	$ 764,701
Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.10
Common Equity Tier 1 Risk Based Capital Amount	$ 1,127,513
Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.1474
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 344,115
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	0.045
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer Amount	$ 535,291
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	0.07
Common Equity Tier 1 Risk Based Capital Required To Be Well Capitalized Amount	$ 497,056
Common Equity Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.065
Tier 1 Risk Based Capital Amount	$ 1,147,513
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.1501
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 458,821
Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	0.06
Tier 1 Risk Based Capital With Capital Conservation Buffer Amount	$ 649,996
Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	0.085
Tier 1 Risk Based Capital Required To Be Well Capitalized Amount	$ 611,761
Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.08
Tier 1 Capital Amount	$ 1,147,513
Tier 1 Capital To Quarterly Average Assets Ratio	0.1052
Tier 1 Capital Required For Capital Adequacy Amount	$ 436,513
Tier 1 Capital Required For Capital Adequacy To Quarterly Average Assets Ratio	0.04
Tier 1 Capital Required To Be Well Capitalized Amount	$ 545,642
Tier 1 Capital Required To Be Well Capitalized To Quarterly Average Assets Ratio	0.05
Pegasus [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 149,997
Total Capital To Risk Weighted Assets Actual Ratio	0.1577
Capital Required For Capital Adequacy Amount	$ 76,071
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	0.08
Capital With Capital Conservation Buffer Amount	$ 99,843
Capital With Capital Conservation To Risk Based Weighted Assets Buffer Ratio	0.105
Capital Required To Be Well Capitalized Amount	$ 95,089
Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.10
Common Equity Tier 1 Risk Based Capital Amount	$ 140,511
Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.1478
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 42,790
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	0.045
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer Amount	$ 66,562
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	0.07
Common Equity Tier 1 Risk Based Capital Required To Be Well Capitalized Amount	$ 61,808
Common Equity Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.065
Tier 1 Risk Based Capital Amount	$ 140,511
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.1478
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 57,053
Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	0.06
Tier 1 Risk Based Capital With Capital Conservation Buffer Amount	$ 80,826
Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	0.085
Tier 1 Risk Based Capital Required To Be Well Capitalized Amount	$ 76,071
Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.08
Tier 1 Capital Amount	$ 140,511
Tier 1 Capital To Quarterly Average Assets Ratio	0.1055
Tier 1 Capital Required For Capital Adequacy Amount	$ 53,263
Tier 1 Capital Required For Capital Adequacy To Quarterly Average Assets Ratio	0.04
Tier 1 Capital Required To Be Well Capitalized Amount	$ 66,579
Tier 1 Capital Required To Be Well Capitalized To Quarterly Average Assets Ratio	0.05
Worthington [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 54,111
Total Capital To Risk Weighted Assets Actual Ratio	0.1227
Capital Required For Capital Adequacy Amount	$ 35,284
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	0.08
Capital With Capital Conservation Buffer Amount	$ 46,310
Capital With Capital Conservation To Risk Based Weighted Assets Buffer Ratio	0.105
Capital Required To Be Well Capitalized Amount	$ 44,105
Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.10
Common Equity Tier 1 Risk Based Capital Amount	$ 50,016
Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.1134
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 19,847
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	0.045
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer Amount	$ 30,873
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	0.07
Common Equity Tier 1 Risk Based Capital Required To Be Well Capitalized Amount	$ 28,668
Common Equity Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.065
Tier 1 Risk Based Capital Amount	$ 50,016
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.1134
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 26,463
Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Ratio	0.06
Tier 1 Risk Based Capital With Capital Conservation Buffer Amount	$ 37,489
Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	0.085
Tier 1 Risk Based Capital Required To Be Well Capitalized Amount	$ 35,284
Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.08
Tier 1 Capital Amount	$ 50,016
Tier 1 Capital To Quarterly Average Assets Ratio	0.0859
Tier 1 Capital Required For Capital Adequacy Amount	$ 23,294
Tier 1 Capital Required For Capital Adequacy To Quarterly Average Assets Ratio	0.04
Tier 1 Capital Required To Be Well Capitalized Amount	$ 29,117
Tier 1 Capital Required To Be Well Capitalized To Quarterly Average Assets Ratio	0.05

Capital with capital conservation buffer.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 505
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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