Gulf Island Fabrication, Inc. Annual report pursuant to Section 13 and 15(d)

Contracts Receivable and Retainage - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2014 Customer	Dec. 31, 2013
Long-term Contracts or Programs Disclosure [Line Items]
Contract receivable	$ 80,448,000	$ 80,448,000	$ 98,579,000
Allowance for bad debt	3,603,000	3,603,000	887,000
Amount of reserved contract receivable	600,000
Top 3 Customer [Member]
Long-term Contracts or Programs Disclosure [Line Items]
Contract receivable	$ 47,100,000	$ 47,100,000
Number of major customers account for 61.6% of contract receivable		3
Percentage of contract receivable		58.50%