Gulf Island Fabrication, Inc. Quarterly report pursuant to Section 13 or 15(d)

Quarterly report pursuant to Section 13 or 15(d)

Cover
- Document and Entity Information
Financial Statements
Notes to Financial Statements
Accounting Policies
- ORGANIZATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)
Notes Tables
Notes Details

Revenue, Contract Assets and Liabilities and Other Contract Matters - Additional Information (Details)

v3.21.1

Revenue, Contract Assets and Liabilities and Other Contract Matters - Additional Information (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) Vechicle
Long Term Contracts Or Programs Disclosure [Line Items]
Reduction of estimated contract price for liquidated damages, amount	$ 0.9		$ 0.6
Towing, Salvage and Rescue Ship
Long Term Contracts Or Programs Disclosure [Line Items]
Change in estimated margins	8.4
Approved change order from increased contract price	9.2
Increased craft labor costs	0.8
Contractual obligation	13.1
Gross profit recognized	9.2
Payment received from change order	$ 8.8
Towing, Salvage and Rescue Ship \| Minimum
Long Term Contracts Or Programs Disclosure [Line Items]
Projects, percent complete (percentage)	15.00%
Towing, Salvage and Rescue Ship \| Maximum
Long Term Contracts Or Programs Disclosure [Line Items]
Projects, percent complete (percentage)	65.00%
Seventy-Vehicle Ferry
Long Term Contracts Or Programs Disclosure [Line Items]
Change in estimated margins	$ 0.7
Projects, percent complete (percentage)	65.00%
Reserve for loss	$ 0.6
Offshore Facility Modules
Long Term Contracts Or Programs Disclosure [Line Items]
Change in estimated margins	0.6
Forty-Vehicle Ferry
Long Term Contracts Or Programs Disclosure [Line Items]
Change in estimated margins			$ 1.2
Number of vehicle ferry projects \| Vechicle			2
Paddlewheel Riverboat and Subsea Components Projects
Long Term Contracts Or Programs Disclosure [Line Items]
Change in estimated margins			$ 0.9
Shipyard
Long Term Contracts Or Programs Disclosure [Line Items]
Change in estimated margins	7.7	$ 1.2
F&S
Long Term Contracts Or Programs Disclosure [Line Items]
Change in estimated margins	$ 0.6	$ 0.9

- Definition

Contract with customer asset cumulative catch-up adjustment to revenue approved change order.

+ References

No definition available.

+ Details

Name:	gifi_ContractWithCustomerAssetCumulativeCatchUpAdjustmentToRevenueApprovedChangeOrder
Namespace Prefix:	gifi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Contract with customer, asset, cumulative catch-up adjustment to revenue, change in estimated margins.

+ References

No definition available.

+ Details

Name:	gifi_ContractWithCustomerAssetCumulativeCatchUpAdjustmentToRevenueChangeInEstimatedMargins
Namespace Prefix:	gifi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Contract with customer asset cumulative catch-up adjustment to revenue increased craft labor costs.

+ References

No definition available.

+ Details

Name:	gifi_ContractWithCustomerAssetCumulativeCatchUpAdjustmentToRevenueIncreasedCraftLaborCosts
Namespace Prefix:	gifi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Contract With Customer, Reserve For Loss.

+ References

No definition available.

+ Details

Name:	gifi_ContractWithCustomerReserveForLoss
Namespace Prefix:	gifi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Gross profit recognized due to cumulative effect impact from projects.

+ References

No definition available.

+ Details

Name:	gifi_GrossProfitRecognizedDueToCumulativeEffectImpactFromProjects
Namespace Prefix:	gifi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Long-term Contracts or Programs Disclosure [Line Items]

+ References

No definition available.

+ Details

Name:	gifi_LongTermContractsOrProgramsDisclosureLineItems
Namespace Prefix:	gifi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of vehicle ferry projects.

+ References

No definition available.

+ Details

Name:	gifi_NumberOfVehicleFerryProjects
Namespace Prefix:	gifi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Projects, Percent Complete

+ References

No definition available.

+ Details

Name:	gifi_ProjectsPercentComplete
Namespace Prefix:	gifi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Revenue variable consideration contract price reduction.

+ References

No definition available.

+ Details

Name:	gifi_RevenueVariableConsiderationContractPriceReduction
Namespace Prefix:	gifi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Transaction price received from change order.

+ References

No definition available.

+ Details

Name:	gifi_TransactionPriceReceivedFromChangeOrder
Namespace Prefix:	gifi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

+ References

No definition available.

+ Details

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

- Details

Name:	srt_ProductOrServiceAxis=gifi_TowingSalvageAndRescueShipMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=gifi_SeventyVehicleFerryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=gifi_OffshoreFacilityModulesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=gifi_FortyVehicleFerryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=gifi_PaddleWheelRiverboatAndSubseaComponentsProjectsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=gifi_ShipyardSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=gifi_FabricationAndServicesSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: