Contract Termination Receivable

No definition available.

Name:	fro_ContractTerminationReceivable
Namespace Prefix:	fro_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Guarantee To Related Party

+ References

No definition available.

+ Details

Name:	fro_GuaranteeToRelatedParty
Namespace Prefix:	fro_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Interest Rate Amortization Profile

+ References

No definition available.

+ Details

Name:	fro_InterestRateAmortizationProfile
Namespace Prefix:	fro_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Joint Venture, Ownership Interest

+ References

No definition available.

+ Details

Name:	fro_JointVentureOwnershipInterest
Namespace Prefix:	fro_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of Vessels Acquired Under SPA

+ References

No definition available.

+ Details

Name:	fro_NumberOfVesselsAcquiredUnderSPA
Namespace Prefix:	fro_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number Of Vessels Chartered In

+ References

No definition available.

+ Details

Name:	fro_NumberOfVesselsCharteredIn
Namespace Prefix:	fro_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Sale Leaseback Agreement, Maximum Amount

+ References

No definition available.

+ Details

Name:	fro_SaleLeasebackAgreementMaximumAmount
Namespace Prefix:	fro_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

Name:	us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

+ Details

Name:	us-gaap_CommonStockSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Value of all classes of common stock held by shareholders. May be all or portion of the number of common shares authorized. These shares exclude common shares repurchased by the entity and held as treasury shares.

+ References

+ Details

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

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

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

- Definition

Gain (loss) related to the termination of a contract between the parties. The termination may be due to many causes including early termination of a lease by a lessee, a breach of contract by one party, or a failure to perform.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

+ Details

Name:	us-gaap_GainLossOnContractTermination
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

For an unclassified balance sheet, amounts due from parties associated with the reporting entity as evidenced by a written promise to pay.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.3)
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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

- Definition

The cash outflow associated with the acquisition of or advances to an entity that is related to it but not strictly controlled (for example, an unconsolidated subsidiary, affiliate, and joint venture or equity method investment) or the acquisition of an additional interest in a subsidiary (controlled entity).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585

+ Details

Name:	us-gaap_PaymentsToAcquireInterestInSubsidiariesAndAffiliates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow for a borrowing supported by a written promise to pay an obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585

+ Details

Name:	us-gaap_RepaymentsOfNotesPayable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Per share or per unit amount of equity securities issued.

+ References

No definition available.

+ Details

Name:	us-gaap_SharesIssuedPricePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of new stock issued during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=fro_ShipFinanceInternationalLimitedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=fro_Termloanfacility62.5millionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=fro_March2020SaleLeasebackAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

SUBSEQUENT EVENTS (Details)			1 Months Ended		12 Months Ended
SUBSEQUENT EVENTS (Details)	Mar. 16, 2020 USD ($) suezmax_tanker	Jan. 23, 2020 USD ($)	Feb. 29, 2020 USD ($) very_large_crude_carrier $ / shares	Jan. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 $ / shares shares	Dec. 31, 2018 $ / shares shares	Dec. 31, 2017 $ / shares shares	Jan. 31, 2019 USD ($)	Jun. 30, 2018
Subsequent Event [Line Items]
Ownership percentage								28.90%	20.00%
Shares issued under ATM program (in shares) \| shares					11,037,273	11,868	0
Share capital, shares issued (in shares) \| shares					196,894,321	169,821,192
Shareholder loan receivable								$ 6,000,000
Cash dividends per share declared (in dollars per share) \| $ / shares					$ 0.1	$ 0	$ 0.3
Subsequent Event
Subsequent Event [Line Items]
Payments to acquire interest in affiliates		$ 800,000
Ownership percentage		17.34%
Shares issued under ATM program (in shares) \| shares				798,000
Shares issued, price per share (in dollars per share) \| $ / shares				$ 7.30
Common stock, value				$ 197,692,321
Share capital, shares issued (in shares) \| shares				197,692,321
Joint venture, ownership interest				15.00%
Shareholder loan receivable				$ 1,500,000
Guarantee To Related Party				50,000,000
Cash dividends per share declared (in dollars per share) \| $ / shares			$ 0.40
Number Of Vessels Acquired Under SPA \| suezmax_tanker	10
SFL \| Subsequent Event
Subsequent Event [Line Items]
Contract termination receivable			$ 3,200,000
Gain on contract termination			$ 7,400,000
Number of vessels chartered in \| very_large_crude_carrier			2
Repayments of notes payable			$ 20,000,000
Term loan facility $62.5 million \| Subsequent Event
Subsequent Event [Line Items]
Principal amount			$ 62,500,000.0
Term of debt			5 years
Interest rate amortization profile			18 years
March 2020 Sale Leaseback Agreement \| Subsequent Event
Subsequent Event [Line Items]
Term of debt	7 years
Interest rate amortization profile	17 years 9 months 18 days
Sale leaseback agreement, maximum amount	$ 544,000,000
London Interbank Offered Rate (LIBOR) \| Term loan facility $62.5 million \| Subsequent Event
Subsequent Event [Line Items]
Basis spread on variable interest rate			1.90%
London Interbank Offered Rate (LIBOR) \| March 2020 Sale Leaseback Agreement \| Subsequent Event
Subsequent Event [Line Items]
Basis spread on variable interest rate	2.30%