XML 73 R62.htm IDEA: XBRL DOCUMENT v3.25.3

Fair Value of Financial Instruments - Changes in Fair Value of Assets Classified in the Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Mortgage banking revenue (loans held for sale)
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Changes in fair value included in noninterest income (expenses)	$ 0	$ (273)	$ 0	$ (139)
Other income | Securities carried at fair value through income
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Changes in fair value included in noninterest income (expenses)	(15)	35	6	25
Non interest income
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Changes in fair value included in noninterest income (expenses)	(15)	(238)	6	(114)
Rabbi Trust assets
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Changes in fair value included in noninterest income (expenses)	(17)	0	(37)	0
Deferred compensation liabilities related to Rabbi Trust assets
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Changes in fair value included in noninterest income (expenses)	17	0	37	0
Noninterest expense
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Changes in fair value included in noninterest income (expenses)	$ 0	$ 0	$ 0	$ 0

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/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 102
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-102

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

+ Details

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

X

- Definition

For each line item in the statement of financial position, the amounts of gains and losses from fair value changes included in earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-SubTopic 10
-Topic 825
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482881/825-10-55-10

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482881/825-10-55-12

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-30

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-32

+ Details

Name:	us-gaap_FairValueOptionChangesInFairValueGainLoss1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=obnk_MortgageBankingRevenueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_OtherIncomeMember
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:

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=obnk_NoninterestIncomeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=obnk_RabbiTrustAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=obnk_DeferredCompensationLiabilitiesRelatedToRabbiTrustAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementLocationAxis=obnk_NoninterestExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: