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Redemption price as percentage of principal amount premium and interest.

+ References

No definition available.

+ Details

Name:	glf_RedemptionPriceAsPercentageOfPrincipalAmountPremiumAndInterest
Namespace Prefix:	glf_
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Balance Type:	na
Period Type:	duration

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
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- Definition

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

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

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Balance Type:	na
Period Type:	instant

- Definition

Amount of debt issuance costs (for example, but not limited to, legal, accounting, broker, and regulatory fees).

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 50

-Section 40

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6850294&loc=d3e12317-112629

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 50

-Section 40

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6850294&loc=d3e12355-112629

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Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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Balance Type:	credit
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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 7

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)

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 9

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20, 22

-Article 5

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

Name:	us-gaap_LongTermDebtFairValue
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Balance Type:	credit
Period Type:	instant

- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

No definition available.

+ Details

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Note 3 - Long-Term Debt (Details)	0 Months Ended	3 Months Ended	6 Months Ended			0 Months Ended		6 Months Ended	12 Months Ended						0 Months Ended		6 Months Ended	0 Months Ended
Note 3 - Long-Term Debt (Details)	Jun. 20, 2013 USD ($)	Jun. 30, 2012 USD ($)	Jun. 30, 2012 USD ($)	Jun. 30, 2013 USD ($)	Dec. 31, 2012 USD ($)	Mar. 14, 2017 Scenario, Forecast [Member] 6.375% Senior Notes [Member] Senior Notes Due 2022 [Member]	Mar. 14, 2013 Scenario, Forecast [Member] 6.375% Senior Notes [Member] Senior Notes Due 2022 [Member]	Jun. 30, 2013 Scenario, Forecast [Member] 6.375% Senior Notes [Member] Senior Notes Due 2022 [Member] USD ($)	Mar. 14, 2021 Scenario, Forecast [Member] 6.375% Senior Notes [Member] Senior Notes Due 2022 [Member]	Mar. 14, 2020 Scenario, Forecast [Member] 6.375% Senior Notes [Member] Senior Notes Due 2022 [Member]	Mar. 14, 2019 Scenario, Forecast [Member] 6.375% Senior Notes [Member] Senior Notes Due 2022 [Member]	Mar. 14, 2018 Scenario, Forecast [Member] 6.375% Senior Notes [Member] Senior Notes Due 2022 [Member]	Mar. 12, 2012 6.375% Senior Notes [Member] Senior Notes Due 2022 [Member] USD ($)	Dec. 31, 2012 7.75% Senior Notes [Member] Old Facility [Member] USD ($)	Dec. 05, 2012 Senior Notes Due 2022 [Member] USD ($)	Jun. 30, 2013 Senior Notes Due 2022 [Member] USD ($)	Jun. 30, 2013 Old Facility [Member] USD ($)	Feb. 25, 2013 Multicurrency Facility Agreement [Member] USD ($)	Jun. 20, 2013 Norweigan Facility Agreement [Member] USD ($)	Jun. 20, 2013 Norweigan Facility Agreement [Member] NOK
Note 3 - Long-Term Debt (Details) [Line Items]
Debt Instrument, Face Amount													$ 300,000,000	$ 160,000,000					$ 100,000,000	600,000,000
Debt Instrument, Interest Rate, Stated Percentage													6.375%	7.75%
Proceeds from Issuance of Debt															200,000,000
Redemption Price As Percentage Of Principal Amount Premium And Interest							100.00%		100.00%	101.063%	102.125%	103.188%
Debt Instrument, Description of Variable Rate Basis						50
Debt Issuance Cost	1,300,000							12,700,000										2,700,000
Gains (Losses) on Extinguishment of Debt		(1,711,000)	(3,641,000)														4,200,000
Long-term Debt, Fair Value																495,700,000
Long-term Debt				500,000,000	500,000,000											501,000,000
Line of Credit Facility, Maximum Borrowing Capacity																		$ 150,000,000