Fair Value of Financial Instruments, Derivatives and Fair Value Disclosures (Details Textual) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Dec. 31, 2014
Fair Value Of Financial Instruments Derivatives And Fair Value Disclousres [Line Items]
Interest Rate Cap Termination Date	Feb. 05, 2017
Interest Rate Cap Agreements Start Date	Feb. 05, 2015
Restricted Cash and Cash Equivalents, Current	$ 118,010	$ 123,178
8.125% notes due 2018 [Member]
Fair Value Of Financial Instruments Derivatives And Fair Value Disclousres [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	8.125%	8.125%
7.5% notes due 2024 [Member]
Fair Value Of Financial Instruments Derivatives And Fair Value Disclousres [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.50%	7.50%
7.5% Election 1 notes due 2021 [Member]
Fair Value Of Financial Instruments Derivatives And Fair Value Disclousres [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.50%	7.50%
7.5% Election 2 notes due 2021 [Member]
Fair Value Of Financial Instruments Derivatives And Fair Value Disclousres [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.50%	7.50%
Interest Rate Cap [Member]
Fair Value Of Financial Instruments Derivatives And Fair Value Disclousres [Line Items]
Increase Derivative Cap Interest Rate	3.00%
OSG Bulk Ships, Inc [Member] \| Interest Rate Cap [Member]
Fair Value Of Financial Instruments Derivatives And Fair Value Disclousres [Line Items]
Derivative Liability, Notional Amount	375,000
Derivative, Cap Interest Rate	2.50%
OSG International, Inc [Member] \| Interest Rate Cap [Member]
Fair Value Of Financial Instruments Derivatives And Fair Value Disclousres [Line Items]
Derivative Liability, Notional Amount	$ 400,000
Derivative, Cap Interest Rate	2.50%

Name:	osgiq_FairValueOfFinancialInstrumentsDerivativesAndFairValueDisclousresLineItems
Namespace Prefix:	osgiq_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

It represents increase derivative cap interest rate.

+ References

No definition available.

+ Details

Name:	osgiq_IncreaseDerivativeCapInterestRate
Namespace Prefix:	osgiq_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

It represents interest rate cap agreements start date.

+ References

No definition available.

+ Details

Name:	osgiq_InterestRateCapAgreementsStartDate
Namespace Prefix:	osgiq_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

It represents interest rate cap termination date.

+ References

No definition available.

+ Details

Name:	osgiq_InterestRateCapTerminationDate
Namespace Prefix:	osgiq_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Cap rate on an interest rate derivative such as an interest rate cap or collar. If market rates exceed the cap rate, a payment or receipt is triggered on the contract.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeCapInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Nominal or face amount used to calculate payments on the derivative liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5579245-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

-URI http://asc.fasb.org/extlink&oid=6519104

+ Details

Name:	us-gaap_DerivativeLiabilityNotionalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against short-term borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. For a classified balance sheet represents the current portion only (the noncurrent portion has a separate concept); there is a separate and distinct element for unclassified presentations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 1

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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

- Details

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

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_InterestRateCapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=osgiq_EightPointOneTwoFivePercentageNotesDueTwoThousandEighteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=osgiq_SevenPointFivePercentageElectionOneNotesDueTwoThousandTwentyOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=osgiq_SevenPointFivePercentageElectionTwoNotesDueTwoThousandTwentyOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=osgiq_SevenPointFivePercentageNotesDueTwoThousandTwentyFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: