v3.26.1

Commitments and Contingencies - Narrative (Details) $ in Millions	1 Months Ended
	Oct. 31, 2025 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Sales tax assessment	$ 15

The amount of sales tax assessment determined by the state or local tax authorities.

No definition available.

Name:	orn_SalesTaxAssessment
Namespace Prefix:	orn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

No definition available.

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