TAX STATUS (Details) - 401(K) Plan	Jun. 30, 2020
TAX STATUS
Determination letter obtained	true
Determination letter date	Jun. 30, 2020
Tax qualification status	us-gaap:QualifiedPlanMember

Date of tax determination letter for employee stock purchase, saving, or similar plan (employee benefit plan (EBP)), in YYYY-MM-DD format.

Name:	us-gaap-ebp_EmployeeBenefitPlanTaxDeterminationLetterDate
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Indicates (true false) whether tax determination letter was obtained by employer of participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanTaxDeterminationLetterObtained
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration

- Definition

Indicates tax qualification status of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-02(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanTaxQualificationStatusExtensibleEnumeration
Namespace Prefix:	us-gaap-ebp_
Data Type:	enum2:enumerationSetItemType
Balance Type:	na
Period Type:	duration

- 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/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanTaxStatusLineItems
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=obt_EBP004Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: