Shareholders' Equity and Regulatory Capital - Bank's Actual Capital Ratios (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Orrstown Financial Services, Inc.
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Actual, Amount, Total capital to risk weighted assets	$ 135,008	$ 119,713
Actual, Amount, Tier 1 capital to risk weighted assets	124,847	110,750
Actual, Amount, CET1 capital to risk weighted assets	124,847
Actual, Amount, Tier 1 capital to average assets	124,847	110,750
Actual, Ratio, Total capital to risk weighted assets	16.80%	16.80%
Actual, Ratio, Tier 1 capital to risk weighted assets	15.60%	15.60%
Actual, Ratio, CET1 capital to risk weighted assets	15.60%
Actual, Ratio, Tier 1 capital to average assets	10.60%	9.50%
Minimum Capital Requirement, Amount, Total capital to risk weighted assets	64,192	56,859
Minimum Capital Requirement, Amount, Tier 1 capital to risk weighted assets	48,144	28,429
Minimum Capital Requirement, Amount, CET1 capital to risk weighted assets	36,108
Minimum Capital Requirement, Amount, Tier 1 capital to average assets	47,110	46,496
Minimum Capital Requirement, Ratio, Total capital to risk weighted assets	8.00%	8.00%
Minimum Capital Requirement, Ratio, Tier 1 capital to risk weighted assets	6.00%	4.00%
Minimum Capital Requirement, Ratio, CET1 capital to risk weighted assets	4.50%
Minimum Capital Requirement, Ratio, Tier 1 capital to average assets	4.00%	4.00%
Orrstown Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Actual, Amount, Total capital to risk weighted assets	132,893	118,540
Actual, Amount, Tier 1 capital to risk weighted assets	122,748	109,581
Actual, Amount, CET1 capital to risk weighted assets	122,748
Actual, Amount, Tier 1 capital to average assets	122,748	109,581
Actual, Ratio, Total capital to risk weighted assets	16.60%	16.70%
Actual, Ratio, Tier 1 capital to risk weighted assets	15.30%	15.40%
Actual, Ratio, CET1 capital to risk weighted assets	15.30%
Actual, Ratio, Tier 1 capital to average assets	10.40%	9.40%
Minimum Capital Requirement, Amount, Total capital to risk weighted assets	64,161	56,835
Minimum Capital Requirement, Amount, Tier 1 capital to risk weighted assets	48,121	28,417
Minimum Capital Requirement, Amount, CET1 capital to risk weighted assets	36,091
Minimum Capital Requirement, Amount, Tier 1 capital to average assets	47,169	46,518
Minimum Capital Requirement, Ratio, Total capital to risk weighted assets	8.00%	8.00%
Minimum Capital Requirement, Ratio, Tier 1 capital to risk weighted assets	6.00%	4.00%
Minimum Capital Requirement, Ratio, CET1 capital to risk weighted assets	4.50%
Minimum Capital Requirement, Ratio, Tier 1 capital to average assets	4.00%	4.00%
Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions, Amount, Total capital to risk weighted assets	80,202	71,043
Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions, Amount, Tier 1 capital to risk weighted assets	64,161	42,626
Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions, Amount, CET1 capital to risk weighted assets	52,131
Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions, Amount, Tier 1 capital to average assets	$ 58,961	$ 58,148
Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio, Total capital to risk weighted assets	10.00%	10.00%
Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio, Tier 1 capital to risk weighted assets	8.00%	6.00%
Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio, CET1 capital to risk weighted assets	6.50%
Minimum to Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio, Tier 1 capital to average assets	5.00%	5.00%

Common Equity Tier 1 Risk Based Capital

No definition available.

Name:	orrf_CommonEquityTier1RiskBasedCapital
Namespace Prefix:	orrf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy

+ References

No definition available.

+ Details

Name:	orrf_CommonEquityTier1RiskBasedCapitalRequiredForCapitalAdequacy
Namespace Prefix:	orrf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Common Equity Tier 1 Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets

+ References

No definition available.

+ Details

Name:	orrf_CommonEquityTier1RiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets
Namespace Prefix:	orrf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Common Equity Tier 1 Risk Based Capital Required To Be Well Capitalized

+ References

No definition available.

+ Details

Name:	orrf_CommonEquityTier1RiskBasedCapitalRequiredToBeWellCapitalized
Namespace Prefix:	orrf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Common Equity Tier 1 Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets

+ References

No definition available.

+ Details

Name:	orrf_CommonEquityTier1RiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Namespace Prefix:	orrf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Common Equity Tier 1 Risk Based Capital To Risk Weighted Assets

+ References

No definition available.

+ Details

Name:	orrf_CommonEquityTier1RiskBasedCapitalToRiskWeightedAssets
Namespace Prefix:	orrf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of total capital as defined in the regulations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 948

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6490092&loc=d3e47304-110998

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 505

-Section 50

-Paragraph 1H

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 505

-Section 50

-Paragraph 1H

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 948

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=6490092&loc=d3e47080-110998

+ Details

Name:	us-gaap_Capital
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The minimum amount of Total Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

+ References

+ Details

Name:	us-gaap_CapitalRequiredForCapitalAdequacy
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The minimum Total risk based capital ratio (total capital divided by risk weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 505

-Section 50

-Paragraph 1H

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=35709795&loc=d3e65071-112826

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 505

-Section 50

-Paragraph 1

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 505

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958570-112826

+ Details

Name:	us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of Total Capital required to be categorized as well as capitalized under the regulatory framework for prompt corrective action.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 505

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826

+ Details

Name:	us-gaap_CapitalRequiredToBeWellCapitalized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The Total risk based capital ratio (total capital divided by risk weighted assets) required to be categorized as "well capitalized", in the regulatory framework for prompt corrective action.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 505

-Section 50

-Paragraph 1

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=35709795&loc=SL5958568-112826

+ Details

Name:	us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Total Capital divided by risk weighted assets as defined in the regulations.

+ References

+ Details

Name:	us-gaap_CapitalToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

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

- Definition

Tier 1 Leverage Capital as defined in the regulations. Also called Core Capital.

+ References

+ Details

Name:	us-gaap_TierOneLeverageCapital
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The minimum amount of Tier 1 Leverage Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

+ References

+ Details

Name:	us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The minimum amount of Tier 1 Leverage Capital for capital adequacy purposes divided by average assets as defined in the regulations.

+ References

+ Details

Name:	us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of Tier 1 Leverage Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

+ References

+ Details

Name:	us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of Tier 1 Leverage Capital required to be categorized as well capitalized divided by average assets as defined in the regulatory framework for prompt corrective action.

+ References

+ Details

Name:	us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Tier 1 Leverage Capital divided by average assets as defined in the regulations.

+ References

+ Details

Name:	us-gaap_TierOneLeverageCapitalToAverageAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Tier 1 Risk Based Capital as defined in the regulations.

+ References

+ Details

Name:	us-gaap_TierOneRiskBasedCapital
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The minimum amount of Tier 1 Risk Based Capital required for capital adequacy purposes under the regulatory framework for prompt corrective action.

+ References

+ Details

Name:	us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The minimum Tier One Capital Ratio (Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action.

+ References

+ Details

Name:	us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of Tier 1 Risk Based Capital required to be categorized as well capitalized under the regulatory framework for prompt corrective action.

+ References

+ Details

Name:	us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The Tier 1 capital ratio (Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action.

+ References

+ Details

Name:	us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Tier 1 capital divided by risk weighted assets as defined by regulations.

+ References

+ Details

Name:	us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	dei_LegalEntityAxis=orrf_OrrstownBankMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=orrf_OrrstownFinancialServicesIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: