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		9 Months Ended
	Oct. 31, 2021 USD ($)	Apr. 19, 2021 USD ($) Vechicle vessel Ship_project drydock	Mar. 31, 2021 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) Vechicle	Sep. 30, 2020 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of drydocks previously supported for shipyard division operations \| drydock		3
Number of vehicle ferry projects \| Vechicle					2
Liabilities					$ 24,722,000			$ 104,981,000
Asset impairments					22,750,000
Change in estimated margins					8,400,000
Approved change order from increased contract price					9,200,000
Increased craft labor costs					800,000
Other (income) expense, net				$ (529,000)	647,000	$ (629,000)
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 vehicle ferry projects \| Vechicle		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					22,800,000
Additional loss related to additional transaction and other costs					2,600,000
Asset impairments			$ 22,800,000
Change in estimated margins				$ 6,700,000		$ 7,400,000
Other (income) expense, net					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					11,000,000.0
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
Closing adjustment returned to related party							$ 200,000
Purchase Agreement \| Bollinger \| Shipyard Transaction \| Subsequent Event
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Deferred transaction price	$ 1,300
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