Vessels, net, Advances for Vessels under Construction (Details) $ in Thousands	6 Months Ended
Jun. 30, 2026 USD ($)
Vessels, net [Abstract]
Beginning balance	$ 0
Additions	18,292
Capitalized Newbuilding vessel monitoring fees	432
Advances paid	11,932
Capitalized expenses	494
Capitalized Imputed interest	376
Foreign currency translation differences	(165)
Ending balance	$ 31,361

Carrying amount as of the balance sheet date of advances for vessels under construction.

No definition available.

Name:	rubi_AdvancesForVesselsUnderConstruction
Namespace Prefix:	rubi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of additions for vessels under construction.

No definition available.

Name:	rubi_AdvancesForVesselsUnderConstructionAdditions
Namespace Prefix:	rubi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of advances paid for vessels under construction.

No definition available.

Name:	rubi_AdvancesForVesselsUnderConstructionAdvancesPaid
Namespace Prefix:	rubi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of capitalized expenses included in advances for vessels under construction.

No definition available.

Name:	rubi_AdvancesForVesselsUnderConstructionCapitalizedExpenses
Namespace Prefix:	rubi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of capitalized imputed interest included in advances for vessels under construction.

No definition available.

Name:	rubi_AdvancesForVesselsUnderConstructionCapitalizedImputedInterest
Namespace Prefix:	rubi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of capitalized newbuilding vessel monitoring fees included in advances for vessels under construction.

No definition available.

Name:	rubi_AdvancesForVesselsUnderConstructionCapitalizedNewbuildingVesselMonitoringFees
Namespace Prefix:	rubi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of foreign currency translation differences included in advances for vessels under construction.

No definition available.

Name:	rubi_AdvancesForVesselsUnderConstructionForeignCurrencyTranslationDifferences
Namespace Prefix:	rubi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

No definition available.

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