Stockholders' Equity - Required Capital Amounts and Company's Respective Ratios (Detail) $ in Thousands	Sep. 30, 2023 USD ($)
Parent Company [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 1,430,965
Total Capital To Risk Weighted Assets Actual Ratio	0.169
Capital Required For Capital Adequacy Amount	$ 677,482
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	0.08
Capital With Capital Conservation Buffer Amount	$ 889,196
Capital With Capital Conservation To Risk Based Weighted Assets Buffer Ratio	0.105
Common Equity Tier 1 Risk Based Capital Amount	$ 1,247,907
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	$ 381,084
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	$ 592,797
Common Equity Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	0.07
Tier 1 Risk Based Capital Amount	$ 1,273,907
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.1504
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 508,112
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	$ 719,825
Tier 1 Risk Based Capital With Capital Conservation Buffer To Risk Weighted Assets Ratio	0.085
Tier 1 Capital Amount	$ 1,273,907
Tier 1 Capital To Quarterly Average Assets Ratio	0.107
Tier 1 Capital Required For Capital Adequacy Amount	$ 476,200
Tier 1 Capital Required For Capital Adequacy To Quartely Average Assets Ratio	0.04
BancFirst [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 1,189,612
Total Capital To Risk Weighted Assets Actual Ratio	0.1636
Capital Required For Capital Adequacy Amount	$ 581,616
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	0.08
Capital With Capital Conservation Buffer Amount	$ 763,371
Capital With Capital Conservation To Risk Based Weighted Assets Buffer Ratio	0.105
Capital Required To Be Well Capitalized Amount	$ 727,020
Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.10
Common Equity Tier 1 Risk Based Capital Amount	$ 1,083,583
Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.149
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 327,159
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	$ 508,914
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	$ 472,563
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	$ 1,103,583
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.1518
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 436,212
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	$ 617,967
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	$ 581,616
Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.08
Tier 1 Capital Amount	$ 1,103,583
Tier 1 Capital To Quarterly Average Assets Ratio	0.1085
Tier 1 Capital Required For Capital Adequacy Amount	$ 406,769
Tier 1 Capital Required For Capital Adequacy To Quartely Average Assets Ratio	0.04
Tier 1 Capital Required To Be Well Capitalized Amount	$ 508,461
Tier 1 Capital Required To Be Well Capitalized To Quartely Average Assets Ratio	0.05
Pegasus [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 143,898
Total Capital To Risk Weighted Assets Actual Ratio	0.1816
Capital Required For Capital Adequacy Amount	$ 63,389
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	0.08
Capital With Capital Conservation Buffer Amount	$ 83,199
Capital With Capital Conservation To Risk Based Weighted Assets Buffer Ratio	0.105
Capital Required To Be Well Capitalized Amount	$ 79,237
Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.10
Common Equity Tier 1 Risk Based Capital Amount	$ 135,463
Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.171
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 35,657
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	$ 55,466
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	$ 51,504
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	$ 135,463
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.171
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 47,542
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	$ 67,351
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	$ 63,389
Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.08
Tier 1 Capital Amount	$ 135,463
Tier 1 Capital To Quarterly Average Assets Ratio	0.1126
Tier 1 Capital Required For Capital Adequacy Amount	$ 48,117
Tier 1 Capital Required For Capital Adequacy To Quartely Average Assets Ratio	0.04
Tier 1 Capital Required To Be Well Capitalized Amount	$ 60,146
Tier 1 Capital Required To Be Well Capitalized To Quartely Average Assets Ratio	0.05
Worthington [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital Amount	$ 50,731
Total Capital To Risk Weighted Assets Actual Ratio	0.1292
Capital Required For Capital Adequacy Amount	$ 31,401
Capital Required For Capital Adequacy to Risk Weighted Assets Ratio	0.08
Capital With Capital Conservation Buffer Amount	$ 41,214
Capital With Capital Conservation To Risk Based Weighted Assets Buffer Ratio	0.105
Capital Required To Be Well Capitalized Amount	$ 39,251
Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.10
Common Equity Tier 1 Risk Based Capital Amount	$ 46,814
Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.1193
Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 17,663
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	$ 27,476
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	$ 25,513
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	$ 46,814
Tier 1 Risk Based Capital To Risk Weighted Assets Ratio	0.1193
Tier 1 Risk Based Capital Required For Capital Adequacy Amount	$ 23,551
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	$ 33,363
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	$ 31,401
Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Ratio	0.08
Tier 1 Capital Amount	$ 46,814
Tier 1 Capital To Quarterly Average Assets Ratio	0.0888
Tier 1 Capital Required For Capital Adequacy Amount	$ 21,086
Tier 1 Capital Required For Capital Adequacy To Quartely Average Assets Ratio	0.04
Tier 1 Capital Required To Be Well Capitalized Amount	$ 26,358
Tier 1 Capital Required To Be Well Capitalized To Quartely Average Assets Ratio	0.05