XML 72 R58.htm IDEA: XBRL DOCUMENT v3.24.1.u1

Fair Value of Financial Instruments - Difference Between Fair Value and Unpaid Principal Balance (Details) - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Option, Quantitative Disclosures [Line Items]
Aggregate Fair Value	$ 21,730,000	$ 23,660,000
Principal Balance/Amortized Cost	21,411,000	23,290,000
Difference	319,000	370,000
Nonaccrual mortgage loans held for sale recorded at fair value	0	0
Loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Aggregate Fair Value	14,975,000	16,852,000
Principal Balance/Amortized Cost	14,596,000	16,475,000
Difference	379,000	377,000
Securities carried at fair value through income
Fair Value, Option, Quantitative Disclosures [Line Items]
Aggregate Fair Value	6,755,000	6,808,000
Principal Balance/Amortized Cost	6,815,000	6,815,000
Difference	$ (60,000)	$ (7,000)

X

- Definition

Fair Value, Option, Aggregate Fair Value

+ References

No definition available.

+ Details

Name:	obnk_FairValueOptionAggregateFairValue
Namespace Prefix:	obnk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Fair Value, Option, Aggregate Unpaid Principal Balance

+ References

No definition available.

+ Details

Name:	obnk_FairValueOptionAggregateUnpaidPrincipalBalance
Namespace Prefix:	obnk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of loans and long-term receivables (other than securities categorized as trading, available-for-sale or held-to-maturity) that have contractual principal amounts and for which the fair value option has been elected.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-28

+ Details

Name:	us-gaap_FairValueOptionAggregateDifferencesLoansAndLongTermReceivables
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-30

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 31
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-31

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-32

+ Details

Name:	us-gaap_FairValueOptionQuantitativeDisclosuresLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Fair value portion of mortgage loans held-for-sale.

+ References

No definition available.

+ Details

Name:	us-gaap_MortgagesHeldForSaleFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=obnk_LoansHeldforSaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=obnk_DebtSecuritiesFVNIMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: