Annual report [Section 13 and 15(d), not S-K Item 405]

Credit Facilities and Debt - Additional Information (Details)

v3.25.0.1
Credit Facilities and Debt - Additional Information (Details) - USD ($)
12 Months Ended
May 03, 2024
Nov. 06, 2023
Dec. 31, 2024
Dec. 31, 2023
Line Of Credit Facility [Line Items]        
Maturity date Jun. 30, 2026      
Surety bonds     $ 28,200,000  
Debt instrument, interest rate terms   principal and interest payable in 15 equal annual installments    
Percentage of provision required from proceeds received in excess of sale of real estate     50.00%  
Proceeds from sale of real estate required to make provision     $ 8,000,000  
Note Agreement        
Line Of Credit Facility [Line Items]        
Stated interest rate (percentage)     2.90%  
Interest expense     $ 600,000 $ 100,000
Short-term premium finance     12,300,000  
Insurance Finance and General Liability Arrangements        
Line Of Credit Facility [Line Items]        
Principal payments       $ 1,300,000
Promissory Note | Note Agreement        
Line Of Credit Facility [Line Items]        
Stated interest rate (percentage)   3.00%    
Debt instrument, issued, principal   $ 20,000,000    
Debt instrument, periodic payment   $ 1,700,000    
Debt instrument, frequency of periodic payment   15    
Debt instrument, maturity date, start   Dec. 30, 2024    
Debt instrument, maturity date, end   Dec. 31, 2038    
Fabrication        
Line Of Credit Facility [Line Items]        
Surety bonds subject to dispute     15,600,000  
Forty Vehicle Ferry Projects        
Line Of Credit Facility [Line Items]        
Surety bonds subject to dispute     12,600,000  
Maximum        
Line Of Credit Facility [Line Items]        
Letter of credit facility     $ 10,000,000  
LC Facility        
Line Of Credit Facility [Line Items]        
Fees on undrawn borrowings (percentage)     0.40%  
Total outstanding letters of credit     $ 1,200,000  
Letter of Credit        
Line Of Credit Facility [Line Items]        
Stated interest rate (percentage)     1.50%