CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Pool revenues, received from companies accounted for by the equity method	$ 13,824	$ 21,837

Revenues earned from Pools that are equity method investments.

No definition available.

Name:	osgiq_EquityMethodInvestmentSummarizedFinancialInformationShippingPoolRevenue
Namespace Prefix:	osgiq_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration