Annual report pursuant to Section 13 and 15(d)

Impairments and (Gain) Loss on Assets Held for Sale - Additional Information (Details)

v3.21.1
Impairments and (Gain) Loss on Assets Held for Sale - Additional Information (Details)
 3 Months Ended 12 Months Ended
Dec. 31, 2020
USD ($)
Deckbarge
machine
Dec. 31, 2020
USD ($)
crane
drydock
Dec. 31, 2019
USD ($)
crane
Deckbarge
machine
Dec. 31, 2018
USD ($)
crane
Deckbarge
machine
Dec. 31, 2017
USD ($)
building
Long Lived Assets Held-for-sale [Line Items]          
Impairment of asset held for sale   $ 1,400,000 $ 8,166,000 $ 2,351,000  
Impairments of assets   3,310,000 17,223,000 4,445,000  
Proceeds from sale of property, plant and equipment   2,020,000 2,217,000 85,247,000  
Impairments of assets removed from AHFS     1,060,000    
Gain (loss) on sale of assets   2,000 584,000 (268,000)  
Gain (loss) on sale of assets   (228,000) 369,000 7,724,000  
Gain (loss) on disposition       7,700,000  
Property, plant and equipment, net $ 67,458,000 67,458,000 70,484,000    
Proceeds from property insurance policy       9,362,000  
Insured event, gain (loss)       3,571,000  
Fabrication Segment          
Long Lived Assets Held-for-sale [Line Items]          
Inventory impairment       2,100,000  
Lake Charles Yard assets          
Long Lived Assets Held-for-sale [Line Items]          
Impairment of asset held for sale 1,000,000.0        
Impairments of assets   1,006,000 2,998,000    
Other Assets          
Long Lived Assets Held-for-sale [Line Items]          
Impairments of assets 900,000 874,000      
Jennings Yard assets          
Long Lived Assets Held-for-sale [Line Items]          
Impairments of assets   29,000 4,578,000    
Inventory And Other Assets          
Long Lived Assets Held-for-sale [Line Items]          
Impairments of assets     421,000 2,094,000  
Held for sale          
Long Lived Assets Held-for-sale [Line Items]          
Property, plant and equipment held for sale 8,214,000 8,214,000 9,006,000 $ 18,000,000.0  
Number of cranes | crane       3  
Impairment of asset held for sale       $ 1,000,000.0  
Costs related to closure of Jennings Yard and Lake Charles Yard $ 600,000        
Number of deck barge sold | Deckbarge 1        
Number of plate machines sold | machine 2        
Proceeds from sale of property, plant and equipment $ 1,700,000        
Asset impairment and (gain) loss on assets held for sale, net 200,000        
Number of bending roll machines | machine       2  
Number of deck barges | Deckbarge       1  
Gain (loss) on sale of assets     400,000    
Held for sale | Former Chief Execute Officer          
Long Lived Assets Held-for-sale [Line Items]          
Charges associated to amounts payable to former chief executive officer     500,000    
Held for sale | Drydock          
Long Lived Assets Held-for-sale [Line Items]          
Impairment of asset held for sale     300,000    
Proceeds from sale of assets     600,000    
Fabrication Division | Held for sale          
Long Lived Assets Held-for-sale [Line Items]          
Property, plant and equipment held for sale $ 8,200,000 $ 8,200,000 $ 9,000,000.0    
Number of cranes | crane   3 3    
Number of drydocks | drydock   2      
Number of bending roll machines | machine     2    
Number of deck barges | Deckbarge     1    
Fabrication Division | Held for sale | Cranes          
Long Lived Assets Held-for-sale [Line Items]          
Impairment of asset held for sale   $ 1,400,000      
Fabrication Division | Held for sale | Cranes and Plate Bending Roll Machines          
Long Lived Assets Held-for-sale [Line Items]          
Impairment of asset held for sale     $ 7,800,000    
South Texas Properties          
Long Lived Assets Held-for-sale [Line Items]          
Gain (loss) on disposition       $ (7,724,000)  
South Texas Properties | Disposed of by sale          
Long Lived Assets Held-for-sale [Line Items]          
Proceeds from sale of productive assets       1,300,000  
Gain (loss) on sale of assets       (300,000)  
South Texas Fabrication Yards, South Yard | Disposed of by sale          
Long Lived Assets Held-for-sale [Line Items]          
Proceeds from sale of assets       55,000,000.0  
Proceeds from sale of productive assets       53,800,000  
Gain (loss) on disposition       3,900,000  
Selling costs       1,200,000  
South Texas Fabrication Yards, North Yard          
Long Lived Assets Held-for-sale [Line Items]          
Property, plant and equipment, net       800,000  
South Texas Fabrication Yards, North Yard | Disposed of by sale          
Long Lived Assets Held-for-sale [Line Items]          
Proceeds from sale of assets       28,000,000.0  
Proceeds from sale of productive assets       27,400,000  
Gain (loss) on disposition       4,100,000  
Selling costs       600,000  
Disposal group, not included in sale       18,800,000  
South Texas Fabrication Yards, North Yard, Assets Under Agreement To Sell | Held for sale          
Long Lived Assets Held-for-sale [Line Items]          
Impairment of asset held for sale       1,400,000  
Insurance recoveries         $ 1,300,000
Insured event, gain (loss)       3,600,000 0
South Texas Fabrication Yards | Held for sale          
Long Lived Assets Held-for-sale [Line Items]          
Insurance settlement       15,400,000  
Proceeds from property insurance policy       9,400,000 6,000,000.0
South Texas Properties, Total Loss Of Buildings | Held for sale          
Long Lived Assets Held-for-sale [Line Items]          
Insurance recoveries         1,500,000
Insured event, gain (loss)         $ 0
South Texas Properties, Total Loss Of Buildings | Held for sale | Building          
Long Lived Assets Held-for-sale [Line Items]          
Number of buildings | building         2
Texas North Yard | Held for sale          
Long Lived Assets Held-for-sale [Line Items]          
Insurance recoveries       9,000,000.0  
Insured event, gain (loss)       $ 0  
F&S | Held for sale          
Long Lived Assets Held-for-sale [Line Items]          
Number of cranes | crane   3      
Shipyard          
Long Lived Assets Held-for-sale [Line Items]          
Number of drydocks | drydock   2