Other Long-Term Liabilities - Components (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Other long-term liabilities
Sale-leaseback arrangement	$ 15,118	$ 19,001
Deferred compensation	1,220	1,194
Accrued liabilities expected to be covered by insurance	410	308
Total other long-term liabilities	$ 16,748	$ 20,503

Amount of obligations related to failed sale leaseback arrangement that will be paid after one year.

No definition available.

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Namespace Prefix:	orn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

n/a

+ References

No definition available.

+ Details

Name:	orn_OtherLongTermLiabilitiesAbstract
Namespace Prefix:	orn_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and due beyond one year (or beyond one operating cycle if longer) to insurance entities to mitigate potential loss from various risks or to satisfy a promise to provide certain coverages to employees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(24))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable beyond one year (or the operating cycle, if longer).

+ References

No definition available.

+ Details

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

- Definition

Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer.

+ References

+ Details

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