XML 108 R91.htm IDEA: XBRL DOCUMENT v3.25.0.1

Mortgage Banking - Narrative (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Mortgage Banking [Abstract]
Gain on sale of MSR asset		$ 410,000	$ 0	$ 0
Mortgage servicing rights assets recognized or recorded during period		0	708,000	2,286,000
Settlement of sale of MSR asset	$ 1,800,000	$ 16,087,000	1,806,000	$ 0
Annual servicing fee income rate		0.25%
Reserve for mortgage loan servicing putback expenses		$ 103,000	$ 127,000

X

- Definition

Gain (Loss) on Sale of Mortgage Servicing Rights

+ References

No definition available.

+ Details

Name:	obnk_GainLossOnSaleOfMortgageServicingRights
Namespace Prefix:	obnk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Mortgage Loan Servicing Putback Expenses, Reserve

+ References

No definition available.

+ Details

Name:	obnk_MortgageLoanServicingPutbackExpensesReserve
Namespace Prefix:	obnk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Servicing Fee Income, Rate

+ References

No definition available.

+ Details

Name:	obnk_ServicingFeeIncomeRate
Namespace Prefix:	obnk_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

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

X

- Definition

The value of new servicing assets, subsequently measured at fair value, acquired or created during the current period through purchases or from transfers of financial assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-3

+ Details

Name:	us-gaap_ServicingAssetAtFairValueAdditions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Decrease in servicing assets subsequently measured at fair value resulting from conveyance of servicing rights to unrelated parties.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-3

+ Details

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