XML 84 R67.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Loans - Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Allowance for Loan and Lease Losses [Roll Forward] |  |  |
Beginning balance | $ 96,868 | $ 87,161 | $ 64,586
Allowance for loan credit losses - BTH merger |  |  | 5,527
Charge-offs | 23,640 | 12,049 | 8,759
Recoveries | 9,152 | 4,242 | 4,194
Provision | 8,680 | 17,514 | 21,613
Ending balance | 91,060 | 96,868 | 87,161
Average balance | $ 7,852,622 | $ 7,442,084 | $ 5,920,465
Net charge-offs to loan average balance | 0.18% | 0.10% | 0.08%
PCD loans acquired |  |  | $ 10,800
Provision for credit losses | $ 7,400 | $ 16,800 | 24,700
Provision for loan credit losses | 8,680 | 17,514 | 21,613
Provision (benefit) for off-balance sheet commitments | (1,200) | 75 | 2,300
Provision (benefit) for held to maturity securities | (13) | (836) | 732
Real Estate | Commercial Real Estate |  |  |
Allowance for Loan and Lease Losses [Roll Forward] |  |  |
Beginning balance | 19,625 | 19,772 | 13,425
Allowance for loan credit losses - BTH merger |  |  | 1
Charge-offs | 480 | 42 | 166
Recoveries | 530 | 140 | 40
Provision | (3,129) | (245) | 6,472
Ending balance | 16,546 | 19,625 | 19,772
Average balance | $ 2,485,800 | $ 2,404,530 | $ 1,951,246
Net charge-offs to loan average balance | 0.00% | 0.00% | 0.01%
Provision for loan credit losses | $ (3,129) | $ (245) | $ 6,472
Real Estate | Construction/ Land/ Land Development |  |  |
Allowance for Loan and Lease Losses [Roll Forward] |  |  |
Beginning balance | 9,990 | 7,776 | 4,011
Allowance for loan credit losses - BTH merger |  |  | 0
Charge-offs | 0 | 0 | 0
Recoveries | 0 | 3 | 211
Provision | (2,592) | 2,211 | 3,554
Ending balance | 7,398 | 9,990 | 7,776
Average balance | $ 1,035,871 | $ 1,015,178 | $ 708,758
Net charge-offs to loan average balance | 0.00% | 0.00% | (0.03%)
Provision for loan credit losses | $ (2,592) | $ 2,211 | $ 3,554
Real Estate | Residential Real Estate |  |  |
Allowance for Loan and Lease Losses [Roll Forward] |  |  |
Beginning balance | 10,619 | 8,230 | 6,116
Allowance for loan credit losses - BTH merger |  |  | 0
Charge-offs | 11 | 27 | 91
Recoveries | 16 | 17 | 102
Provision | 1,830 | 2,399 | 2,103
Ending balance | 12,454 | 10,619 | 8,230
Average balance | $ 1,799,963 | $ 1,629,589 | $ 1,143,190
Net charge-offs to loan average balance | 0.00% | 0.00% | 0.00%
Provision for loan credit losses | $ 1,830 | $ 2,399 | $ 2,103
Commercial and industrial |  |  |
Allowance for Loan and Lease Losses [Roll Forward] |  |  |
Beginning balance | 55,330 | 50,148 | 40,146
Allowance for loan credit losses - BTH merger |  |  | 5,525
Charge-offs | 22,787 | 11,833 | 8,459
Recoveries | 8,583 | 4,068 | 3,825
Provision | 12,323 | 12,947 | 9,111
Ending balance | 53,449 | 55,330 | 50,148
Average balance | $ 2,087,361 | $ 2,054,081 | $ 1,675,719
Net charge-offs to loan average balance | 0.68% | 0.38% | 0.28%
Provision for loan credit losses | $ 12,323 | $ 12,947 | $ 9,111
Mortgage Warehouse Lines of Credit |  |  |
Allowance for Loan and Lease Losses [Roll Forward] |  |  |
Beginning balance | 529 | 379 | 340
Allowance for loan credit losses - BTH merger |  |  | 0
Charge-offs | 0 | 0 | 0
Recoveries | 0 | 0 | 0
Provision | (28) | 150 | 39
Ending balance | 501 | 529 | 379
Average balance | $ 420,665 | $ 314,079 | $ 420,639
Net charge-offs to loan average balance | 0.00% | 0.00% | 0.00%
Provision for loan credit losses | $ (28) | $ 150 | $ 39
Consumer |  |  |
Allowance for Loan and Lease Losses [Roll Forward] |  |  |
Beginning balance | 775 | 856 | 548
Allowance for loan credit losses - BTH merger |  |  | 1
Charge-offs | 362 | 147 | 43
Recoveries | 23 | 14 | 16
Provision | 276 | 52 | 334
Ending balance | 712 | 775 | 856
Average balance | $ 22,962 | $ 24,627 | $ 20,913
Net charge-offs to loan average balance | 1.48% | 0.54% | 0.13%
Provision for loan credit losses | $ 276 | $ 52 | $ 334

X
- Definition Credit Loss, Expense (Reversal) + References No definition available. + Details
Name: | obnk_CreditLossExpenseReversal
Namespace Prefix: | obnk_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Financing Receivable, Excluding Accrued Interest, Purchased with Credit Deterioration, Loans Acquired + References No definition available. + Details
Name: | obnk_FinancingReceivableExcludingAccruedInterestPurchasedWithCreditDeteriorationLoansAcquired
Namespace Prefix: | obnk_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Percentage of writeoff after recovery to average financing receivables outstanding. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph a -Subparagraph (4) -Publisher SEC + Details
Name: | srt_FinancingReceivableWriteoffAfterRecoveryToAverageOutstandingPercent
Namespace Prefix: | srt_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_AllowanceForLoanAndLeaseLossesRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of credit loss expense (reversal of expense) on investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_DebtSecuritiesHeldToMaturityExcludingAccruedInterestCreditLossExpenseReversal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, excluding accrued interest, of increase in allowance for credit loss on financing receivable from recovery. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-6 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of allowance for credit loss at acquisition date of financing receivable purchased with credit deterioration. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 19 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-19 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestPurchasedWithCreditDeteriorationAllowanceForCreditLossAtAcquisitionDate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Average amount outstanding, before allowance for credit loss, of financing receivables. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1402 -Paragraph a -Publisher SEC Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1402 -Paragraph b -Subparagraph (1) -Publisher SEC Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph a -Subparagraph (4) -Publisher SEC + Details
Name: | us-gaap_FinancingReceivablesBeforeAllowanceForCreditLossAverageAmountOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of expense (reversal of expense) for expected credit loss for off-balance sheet credit exposure. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=obnk_RealEstatePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=obnk_ConstructionLandandLandDevelopmentLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ResidentialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=obnk_MortgageWarehousePortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |