Revenue, Contract Assets and Liabilities and Other Contract Matters (Tables)
   | 
3 Months Ended | 
Mar. 31, 2022  | 
| Revenue From Contract With Customer [Abstract] | 
 
 | 
| Summary of Disaggregation of Revenue | 
 The following tables summarize revenue for each of our operating segments, disaggregated by contract type, for the three months ended March 31, 2022 and 2021 (in thousands): 
  
| 
   
 | 
   
 | 
 Three Months Ended March 31, 2022 
 | 
   
 | 
 
| 
   
 | 
   
 | 
 Services 
 | 
   
 | 
   
 | 
 Fabrication 
 | 
   
 | 
   
 | 
 Shipyard 
 | 
   
 | 
   
 | 
 Eliminations 
 | 
   
 | 
   
 | 
 Total 
 | 
   
 | 
 
| 
 Fixed-price and unit-rate(1) 
 | 
   
 | 
 $ 
 | 
 1,609 
 | 
   
 | 
   
 | 
 $ 
 | 
 5,044 
 | 
   
 | 
   
 | 
 $ 
 | 
 2,497 
 | 
   
 | 
   
 | 
 $ 
 | 
 (1 
 | 
 ) 
 | 
   
 | 
 $ 
 | 
 9,149 
 | 
   
 | 
 
| 
 T&M(2) 
 | 
   
 | 
   
 | 
 18,463 
 | 
   
 | 
   
 | 
   
 | 
 573 
 | 
   
 | 
   
 | 
   
 | 
 — 
 | 
   
 | 
   
 | 
   
 | 
 — 
 | 
   
 | 
   
 | 
   
 | 
 19,036 
 | 
   
 | 
 
| 
 Other 
 | 
   
 | 
   
 | 
 592 
 | 
   
 | 
   
 | 
   
 | 
 — 
 | 
   
 | 
   
 | 
   
 | 
 — 
 | 
   
 | 
   
 | 
   
 | 
 (91 
 | 
 ) 
 | 
   
 | 
   
 | 
 501 
 | 
   
 | 
 
| 
 Total 
 | 
   
 | 
 $ 
 | 
 20,664 
 | 
   
 | 
   
 | 
 $ 
 | 
 5,617 
 | 
   
 | 
   
 | 
 $ 
 | 
 2,497 
 | 
   
 | 
   
 | 
 $ 
 | 
 (92 
 | 
 ) 
 | 
   
 | 
 $ 
 | 
 28,686 
 | 
   
 | 
 
 
 
  
| 
   
 | 
   
 | 
 Three Months Ended March 31, 2021 
 | 
   
 | 
 
| 
   
 | 
   
 | 
 Services 
 | 
   
 | 
   
 | 
 Fabrication 
 | 
   
 | 
   
 | 
 Shipyard 
 | 
   
 | 
   
 | 
 Eliminations 
 | 
   
 | 
   
 | 
 Total 
 | 
   
 | 
 
| 
 Fixed-price and unit-rate(1) 
 | 
   
 | 
 $ 
 | 
 321 
 | 
   
 | 
   
 | 
 $ 
 | 
 11,018 
 | 
   
 | 
   
 | 
 $ 
 | 
 5,130 
 | 
   
 | 
   
 | 
 $ 
 | 
 (190 
 | 
 ) 
 | 
   
 | 
 $ 
 | 
 16,279 
 | 
   
 | 
 
| 
 T&M(2) 
 | 
   
 | 
   
 | 
 5,551 
 | 
   
 | 
   
 | 
   
 | 
 718 
 | 
   
 | 
   
 | 
   
 | 
 — 
 | 
   
 | 
   
 | 
   
 | 
 — 
 | 
   
 | 
   
 | 
   
 | 
 6,269 
 | 
   
 | 
 
| 
 Other 
 | 
   
 | 
   
 | 
 1,634 
 | 
   
 | 
   
 | 
   
 | 
 — 
 | 
   
 | 
   
 | 
   
 | 
 — 
 | 
   
 | 
   
 | 
   
 | 
 (397 
 | 
 ) 
 | 
   
 | 
   
 | 
 1,237 
 | 
   
 | 
 
| 
 Total 
 | 
   
 | 
 $ 
 | 
 7,506 
 | 
   
 | 
   
 | 
 $ 
 | 
 11,736 
 | 
   
 | 
   
 | 
 $ 
 | 
 5,130 
 | 
   
 | 
   
 | 
 $ 
 | 
 (587 
 | 
 ) 
 | 
   
 | 
 $ 
 | 
 23,785 
 | 
   
 | 
 
 
 
  
| 
   
 | 
 (1) 
 | 
 Revenue is recognized as the contract is progressed over time. 
 | 
 
 
 
| 
   
 | 
 (2) 
 | 
 Revenue is recognized at contracted rates when the work is performed and costs are incurred. 
 | 
 
 
 
 | 
| Summary of Remaining Performance Obligation by Operating Segment | 
 The following table summarizes our remaining performance obligations by operating segment at March 31, 2022 (in thousands): 
  
| 
   
 | 
   
 | 
 Performance 
Obligations 
 | 
   
 | 
 
| 
 Services 
 | 
   
 | 
 $ 
 | 
 1,237 
 | 
   
 | 
 
| 
 Fabrication 
 | 
   
 | 
   
 | 
 7,027 
 | 
   
 | 
 
| 
 Shipyard 
 | 
   
 | 
   
 | 
 7,611 
 | 
   
 | 
 
| 
 Total 
 | 
   
 | 
 $ 
 | 
 15,875 
 | 
   
 | 
 
 
 
  
 | 
| Summary of Contract with Customer, Asset and Liability | 
Information with respect to contracts that were incomplete at March 31, 2022 and December 31, 2021, is as follows (in thousands):
   
| 
   
 | 
   
 | 
 March 31, 
 | 
   
 | 
   
 | 
 December 31, 
 | 
   
 | 
 
| 
   
 | 
   
 | 
 2022 
 | 
   
 | 
   
 | 
 2021 
 | 
   
 | 
 
| 
 Contract assets(1), (2) 
 | 
   
 | 
 $ 
 | 
 2,694 
 | 
   
 | 
   
 | 
 $ 
 | 
 4,759 
 | 
   
 | 
 
| 
 Contract liabilities(3), (4), (5) 
 | 
   
 | 
   
 | 
 (4,198 
 | 
 ) 
 | 
   
 | 
   
 | 
 (6,648 
 | 
 ) 
 | 
 
| 
 Contracts in progress, net 
 | 
   
 | 
 $ 
 | 
 (1,504 
 | 
 ) 
 | 
   
 | 
 $ 
 | 
 (1,889 
 | 
 ) 
 | 
 
 
 
  
| 
   
 | 
 (1) 
 | 
 The decrease in contract assets compared to December 31, 2021, was primarily due to decreased unbilled positions on various projects within our Fabrication Division.  
 | 
 
 
 
| 
   
 | 
 (2) 
 | 
 Contract assets at March 31, 2022 and December 31, 2021, excludes $4.3 million and $2.3 million, respectively, associated with revenue recognized in excess of amounts billed for which we have an unconditional right to the consideration. Such amounts are reflected within contract receivables. 
 | 
 
 
 
| 
   
 | 
 (3) 
 | 
 The decrease in contract liabilities compared to December 31, 2021, was primarily due to a decrease in accrued contract losses and the unwind of advance payments on our forty-vehicle ferry projects within our Shipyard Division.  
 | 
 
 
 
| 
   
 | 
 (4) 
 | 
 Revenue recognized during the three months ended March 31, 2022 and 2021, related to amounts included in our contract liabilities balance at December 31, 2021 and 2020, was $2.1 million and $1.8 million, respectively.  
 | 
 
 
 
| 
   
 | 
 (5) 
 | 
 Contract liabilities at March 31, 2022 and December 31, 2021, includes accrued contract losses of $2.9 million and $3.9 million, respectively. See “Changes in Project Estimates” below for further discussion of our accrued contract losses. 
 | 
 
 
 
 |