DERIVATIVE FINANCIAL INSTRUMENTS - Summary of Effect of Derivative Financial Instruments on OCI and Net Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative	$ 710	$ (458)	$ 1,682	$ (1,374)
Amount of Gain Reclassified from AOCI into Income	37	0	37	0
Amount of Gain (Loss) Recognized in Income	121	(214)	94	(395)
Interest rate products
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivative	673	(458)	1,645	(1,374)
Interest rate products \| Location, Statement of Income, Balance [Axis]: us-gaap:InterestExpenseOperating
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain Reclassified from AOCI into Income	37	0	37	0
Interest rate products \| Location, Statement of Income, Balance [Axis]: us-gaap:OtherNoninterestExpense
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in Income	121	(144)	46	(396)
Interest rate swaps \| Location, Statement of Income, Balance [Axis]: us-gaap:InterestAndFeeIncomeLoansAndLeases \| Interest rate swaps - commercial loans
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in Income	0	0	0	(1)
Risk participation agreements \| Location, Statement of Income, Balance [Axis]: us-gaap:OtherNoninterestExpense
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in Income	3	(2)	4	1
Interest rate lock commitments with customers \| Location, Statement of Income, Balance [Axis]: orrf:FeesAndCommissionsMortgageBankingAndServicesNet
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in Income	5	(58)	30	35
Forward sale commitments \| Location, Statement of Income, Balance [Axis]: orrf:FeesAndCommissionsMortgageBankingAndServicesNet
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Amount of Gain (Loss) Recognized in Income	$ (8)	$ (10)	$ 14	$ (35)