SHAREHOLDERS’ EQUITY AND REGULATORY CAPITAL - Summary of Actual and Required Capital Amounts and Ratios (Details) $ in Thousands	Mar. 31, 2026 USD ($)	Dec. 31, 2025 USD ($)
Orrstown Financial Services, Inc.
Total risk-based capital:
Actual, Amount	$ 601,948	$ 587,354
Actual, Ratio	0.135	0.133
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Amount	$ 467,464	$ 463,702
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Ratio	0.105	0.105
Tier 1 risk-based capital:
Actual, Amount	$ 532,294	$ 514,572
Actual, Ratio	0.120	0.117
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Amount	$ 378,423	$ 375,378
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Ratio	0.085	0.085
Tier 1 common equity risk-based capital:
Actual, Amount	$ 524,305	$ 506,643
Actual, Ratio	11.80%	11.50%
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Amount	$ 311,643	$ 309,135
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Ratio	7.00%	7.00%
Tier 1 leverage capital:
Actual, Amount	$ 532,294	$ 514,572
Actual, Ratio	0.097	0.095
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Amount	$ 218,617	$ 217,008
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Ratio	0.040	0.040
Orrstown Bank
Total risk-based capital:
Actual, Amount	$ 603,598	$ 588,026
Actual, Ratio	0.136	0.133
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Amount	$ 467,416	$ 463,671
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Ratio	0.105	0.105
To Be Well Capitalized Under Prompt Corrective Action Regulations, Amount	$ 445,158	$ 441,592
To Be Well Capitalized Under Prompt Corrective Action Regulations, Ratio	0.100	0.100
Tier 1 risk-based capital:
Actual, Amount	$ 557,371	$ 538,598
Actual, Ratio	0.125	0.122
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Amount	$ 378,384	$ 375,353
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Ratio	0.085	0.085
To Be Well Capitalized Under Prompt Corrective Action Regulations, Amount	$ 356,127	$ 353,273
To Be Well Capitalized Under Prompt Corrective Action Regulations, Ratio	0.080	0.080
Tier 1 common equity risk-based capital:
Actual, Amount	$ 557,371	$ 538,598
Actual, Ratio	12.50%	12.20%
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Amount	$ 311,611	$ 309,114
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Ratio	7.00%	7.00%
To Be Well Capitalized Under Prompt Corrective Action Regulations, Amount	$ 289,353	$ 287,035
To Be Well Capitalized Under Prompt Corrective Action Regulations, Ratio	6.50%	6.50%
Tier 1 leverage capital:
Actual, Amount	$ 557,371	$ 538,598
Actual, Ratio	0.102	0.099
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Amount	$ 218,791	$ 217,148
For Capital Adequacy Purposes (includes applicable capital conservation buffer), Ratio	0.040	0.040
To Be Well Capitalized Under Prompt Corrective Action Regulations, Amount	$ 273,489	$ 271,435
To Be Well Capitalized Under Prompt Corrective Action Regulations, Ratio	0.050	0.050