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Revenue, Contract Assets and Liabilities and Other Contract Matters - Additional Information (Details) | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2021 USD ($) | Jun. 30, 2020 USD ($) | Jun. 30, 2021 USD ($) Vechicle | Jun. 30, 2020 USD ($) Vechicle | Dec. 31, 2020 USD ($)
Long Term Contracts Or Programs Disclosure [Line Items] |  |  |  |  |
Number of vehicle ferry projects | Vechicle |  |  | 2 |  |
Reduction of estimated contract price for liquidated damages, amount | $ 900,000 |  | $ 900,000 |  | $ 600,000
Shipyard |  |  |  |  |
Long Term Contracts Or Programs Disclosure [Line Items] |  |  |  |  |
Change in estimated margins | 900,000 |  | 1,700,000 | $ 1,200,000 |
F&S |  |  |  |  |
Long Term Contracts Or Programs Disclosure [Line Items] |  |  |  |  |
Change in estimated margins | 1,900,000 | $ 1,000,000.0 | 2,000,000.0 | 1,900,000 |
Offshore Modules Project, Material Supply Project and Subsea Structures Project |  |  |  |  |
Long Term Contracts Or Programs Disclosure [Line Items] |  |  |  |  |
Change in estimated margins | 1,900,000 |  | 2,000,000.0 |  |
Seventy-Vehicle Ferry |  |  |  |  |
Long Term Contracts Or Programs Disclosure [Line Items] |  |  |  |  |
Change in estimated margins | $ 900,000 |  | $ 1,700,000 |  |
Projects, percent complete (percentage) | 73.00% |  | 73.00% |  |
Reserve for loss | $ 800,000 |  | $ 800,000 |  |
Paddlewheel Riverboat and Subsea Components Projects |  |  |  |  |
Long Term Contracts Or Programs Disclosure [Line Items] |  |  |  |  |
Change in estimated margins |  | 500,000 |  | 1,400,000 |
Jacket and Deck |  |  |  |  |
Long Term Contracts Or Programs Disclosure [Line Items] |  |  |  |  |
Change in estimated margins |  | 500,000 |  | $ 500,000 |
Forty-Vehicle Ferry |  |  |  |  |
Long Term Contracts Or Programs Disclosure [Line Items] |  |  |  |  |
Number of vehicle ferry projects | Vechicle |  |  |  | 2 |
Change in estimated margins |  | $ 0 |  | $ 1,200,000 |

X
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- Details
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- Details
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- Details
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