Annual report pursuant to Section 13 and 15(d)

Property, Plant and Equipment and Leased Facilities and Equipment - Additional Information (Details)

v3.21.1
Property, Plant and Equipment and Leased Facilities and Equipment - Additional Information (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
USD ($)
ft²
a
Renewal_options
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Property, Plant and Equipment [Line Items]      
Depreciation and lease asset amortization $ 8,617 $ 9,564 $ 10,350
Operating lease, right-of-use asset 1,700    
Current lease liability $ 600    
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] us-gaap:LiabilitiesCurrent    
Long-term lease liability $ 2,000    
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] Other noncurrent liabilities    
Lease agreement expenses $ 1,500 1,800 $ 1,900
Operating lease payments $ 1,800 $ 2,000  
Operating lease, term of contract 4 years    
Operating lease, weighted-average discount rate (percentage) 6.70%    
Houston, Texas      
Property, Plant and Equipment [Line Items]      
Office space area of leased premises (in sqft or acres) | ft² 17,000    
Jennings, Louisiana      
Property, Plant and Equipment [Line Items]      
Office space area of leased premises (in sqft or acres) | a 180    
Lease description During the fourth quarter 2020, we closed our Jennings Yard and do not intend to exercise our renewal options. See Note 3 for discussion of our closure of the Jennings Yard    
Jennings, Louisiana | Prospect Shipyard      
Property, Plant and Equipment [Line Items]      
Lease renewal options | Renewal_options 2    
Lease renewal term 10 years    
Lake Charles, Louisiana      
Property, Plant and Equipment [Line Items]      
Office space area of leased premises (in sqft or acres) | a 10    
Lease description During the fourth quarter 2020, we closed our Lake Charles Yard and do not intend to exercise our renewal options. See Note 3 for discussion of our closure of the Lake Charles Yard    
Lake Charles, Louisiana | Prospect Shipyard      
Property, Plant and Equipment [Line Items]      
Lease renewal options | Renewal_options 3    
Lease renewal term 5 years    
Metairie, Louisiana      
Property, Plant and Equipment [Line Items]      
Office space area of leased premises (in sqft or acres) | ft² 7,600    
Lease maturity date 2025-12