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

Quarterly report pursuant to Section 13 or 15(d)

Shipyard Transaction and Discontinued Operations - Additional Information (Details)

Shipyard Transaction and Discontinued Operations - Additional Information (Details)		3 Months Ended			6 Months Ended
	Apr. 19, 2021 USD ($) Vechicle vessel Ship_project drydock	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) Vechicle	Jun. 30, 2020 USD ($) Vechicle	Dec. 31, 2020 USD ($)
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of vehicle ferry projects \| Vechicle					2
Liabilities		$ 38,340,000			$ 38,340,000		$ 104,981,000
Asset impairments					22,750,000
Other (income) expense, net		660,000			647,000	$ (100,000)
Forty-Vehicle Ferry
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of vehicle ferry projects \| Vechicle						2
Change in estimated margins				$ 0		$ 1,200,000
Towing Salvage and Rescue Ship
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Change in estimated margins					8,400,000
Approved change order from increased contract price					9,200,000
Increased craft labor costs					800,000
Shipyard Transaction
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of research vessels projects \| vessel	3
Number of divested shipyard contracts \| Ship_project	5
Number of drydocks \| drydock	4
Number of drydocks previously supported for shipyard division operations \| drydock	3
Number of MPSV projects \| vessel	2
Pre tax loss on estimated carry value of net assets sold					25,300,000
Estimated loss related to impairment of long lived assets and transaction costs			$ 23,400,000
Additional loss related to additional transaction and other costs		1,900,000
Asset impairments			22,800,000
Change in estimated margins				$ 600,000		$ 600,000
Other (income) expense, net		600,000			600,000
Shipyard Transaction \| Retained Shipyard Contracts And Other Shipyard Division Liabilities
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Liabilities		11,900,000			11,900,000
Shipyard Transaction \| Forty-Vehicle Ferry
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of vehicle ferry projects \| Vechicle	3
Purchase Agreement \| Bollinger \| Shipyard Transaction
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Transaction price	$ 28,600,000
Net of estimated transaction and other costs	26,100,000
Transaction price on closing date	26,400,000
Deferred transaction price	2,200,000
Estimate change in working capital for divested shipyard contracts	8,000,000.0
Actual changes in working capital for divested shipyard contracts	$ 7,800,000	4,800,000	$ 3,000,000.0
Closing adjustment returned to related party		200,000			200,000
Purchase Agreement \| Bollinger \| Shipyard Transaction \| Prepaid Expenses and Other Assets
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Prepaid expenses and other assets		$ 2,200,000			$ 2,200,000