Commitments and Contingencies	12 Months Ended
Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	12. COMMITMENTS AND CONTINGENCIES Commercial commitments Performance and bid bonds are customarily required for dredging and marine construction projects. The Company has bonding agreements with Argonaut Insurance Company (“Argo”), Berkley Insurance Company, Chubb Surety (“Chubb”), Travelers Casualty and Surety Company of America (“Travelers”), Zurich American Insurance Company, and Liberty Mutual Insurance Company (“Liberty”), under which the Company can obtain performance, bid and payment bonds. The Company currently has outstanding bonds with Argo, Chubb, Travelers, and Liberty. Bid bonds are generally obtained for a percentage of bid value and amounts outstanding typically range from $1,000 to $10,000. At December 31, 2022, the Company had outstanding performance bonds with a notional amount of approximately $730,276. The revenue value remaining in backlog related to the projects totaled approximately $308,515. Certain foreign projects performed by the Company have warranty periods, typically spanning no more than one to three years beyond project completion, whereby the Company retains responsibility to maintain the project site to certain specifications during the warranty period. Generally, any potential liability of the Company is mitigated by insurance, shared responsibilities with consortium partners, and/or recourse to owner-provided specifications. Legal proceedings and other contingencies As is customary with negotiated contracts and modifications or claims to competitively bid contracts with the federal government, the government has the right to audit the books and records of the Company to ensure compliance with such contracts, modifications, or claims, and the applicable federal laws. The government has the ability to seek a price adjustment based on the results of such audit. Any such audits have not had, and are not expected to have, a material impact on the financial position, operations, or cash flows of the Company. Various legal actions, claims, assessments and other contingencies arising in the ordinary course of business are pending against the Company and certain of its subsidiaries. The Company will defend itself vigorously on all matters. These matters are subject to many uncertainties, and it is possible that some of these matters could ultimately be decided, resolved, or settled adversely to the Company. Although the Company is subject to various claims and legal actions that arise in the ordinary course of business, except as described below, the Company is not currently a party to any material legal proceedings or environmental claims. The Company records an accrual when it is probable a liability has been incurred and the amount of loss can be reasonably estimated. The Company does not believe any of these proceedings, individually or in the aggregate, would be expected to have a material effect on results of operations, cash flows or financial condition. On April 23, 2014, the Company completed the sale of NASDI, LLC (“NASDI”) and Yankee Environmental Services, LLC (“Yankee”), which together comprised the Company’s historical demolition business, to a privately-owned demolition company. Under the terms of the agreement, the Company received cash of $5,309 and retained the right to receive additional proceeds based upon future collections of outstanding accounts receivable and work in process existing at the date of close. On January 14, 2015, the Company and its subsidiary, NASDI Holdings, LLC, brought an action in the Delaware Court of Chancery to enforce the terms of the Company's agreement to sell NASDI and Yankee. The Company seeks specific performance of the buyer’s obligation to collect and to remit the additional proceeds, and other related relief. Defendants have filed counterclaims alleging that the Company misrepresented the quality of its contracts and receivables prior to the sale. The Company denies defendants’ allegations. In addition, the Company has been granted a judgment in the amount of $21,934 based upon the buyer’s default of its obligations to indemnify the Company for losses resulting from failure to perform in accordance with terms of surety performance bond. On April 11, 2022, the Supreme Court of Delaware issued its decision denying that appeal and affirming the Chancery Court judgment. The Company continues to aggressively pursue collection from the buyer on outstanding amounts owed under the sale and the indemnification. An estimate of a range of potential gains or losses relating to these matters cannot reasonably be made. On April 22, 2021, the U.S. Attorney’s Office for the Eastern District of Louisiana filed a bill of information against the Company charging the Company with a negligent discharge violation of the Clean Water Act (the "CWA") arising from a September 2016 oil spill. The spill occurred during the Company’s Cheniere Ronquille project and resulted in the discharge of around one hundred sixty barrels of crude oil in Bay Long, Louisiana. The Company cooperated with the U.S. Attorney’s Office and other relevant agencies in their investigation of the oil spill and on June 15, 2021, the Company pleaded guilty to the misdemeanor violation alleged in the bill of information and agreed to pay a fine of $1,000. In the first quarter of 2022, the Company entered into a settlement of a civil suit arising from the same matter which was primarily covered by its insurance policies. On June 14, 2022, the Company was sentenced in the criminal matter, and paid a fine of $1,000. The Company had previously deposited $2,000 into the registry of the court to pay any ordered restitution; however, the Company was not ordered to pay any restitution and the deposited funds, less the amount of the fine and administrative costs, were returned to the Company. The CWA provides that, upon an entity’s conviction of certain offenses, the entity is automatically disqualified from eligibility to receive certain federal contracts, if it will perform any part of the awarded contract at the facility giving rise to the conviction (called the “violating facility”). Accordingly, the Court’s entry of the Company’s conviction under the CWA resulted in the automatic disqualification of the Company’s eligibility to be awarded contracts at the violating facility, which the federal suspension and debarment officer (the “SDO”) determined to be the Company’s field office for the Cheniere Ronquille project, located at 28465 Hwy 23, Port Sulphur, Louisiana. The disqualification was imposed on June 23, 2022, and only applied to the Port Sulphur facility and not the Company as a whole. On the same day, June 23, 2022, the SDO issued a decision reinstating the Company’s Port Sulphur facility based on the SDO’s determination that the Company had addressed the causes of the CWA violation. This matter is now fully resolved and will not have any future impact on the Company’s business, financial condition or results of operations. Lease obligations The Company leases certain operating equipment and office facilities under long-term operating leases expiring at various dates through 2030. The equipment leases contain renewal or purchase options that specify prices at the then fair value upon the expiration of the lease terms. The leases also contain default provisions that are triggered by an acceleration of debt maturity under the terms of the Company’s Amended Credit Agreement, or, in certain instances, cross default to other equipment leases and certain lease arrangements require that the Company maintain certain financial ratios comparable to those required by its Amended Credit Agreement. Additionally, the leases typically contain provisions whereby the Company indemnifies the lessors for the tax treatment attributable to such leases based on the tax rules in place at lease inception. The tax indemnifications do not have a contractual dollar limit. To date, no lessors have asserted any claims against the Company under these tax indemnification provisions.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2022

Commitments and Contingencies Disclosure [Abstract]

12. COMMITMENTS AND CONTINGENCIES

Commercial commitments

Performance and bid bonds are customarily required for dredging and marine construction projects. The Company has bonding agreements with Argonaut Insurance Company (“Argo”), Berkley Insurance Company, Chubb Surety (“Chubb”), Travelers Casualty and Surety Company of America (“Travelers”), Zurich American Insurance Company, and Liberty Mutual Insurance Company (“Liberty”), under which the Company can obtain performance, bid and payment bonds. The Company currently has outstanding bonds with Argo, Chubb, Travelers, and Liberty. Bid bonds are generally obtained for a percentage of bid value and amounts outstanding typically range from $1,000 to $10,000. At December 31, 2022, the Company had outstanding performance bonds with a notional amount of approximately $730,276. The revenue value remaining in backlog related to the projects totaled approximately $308,515.

Certain foreign projects performed by the Company have warranty periods, typically spanning no more than one to three years beyond project completion, whereby the Company retains responsibility to maintain the project site to certain specifications during the warranty period. Generally, any potential liability of the Company is mitigated by insurance, shared responsibilities with consortium partners, and/or recourse to owner-provided specifications.

Legal proceedings and other contingencies

As is customary with negotiated contracts and modifications or claims to competitively bid contracts with the federal government, the government has the right to audit the books and records of the Company to ensure compliance with such contracts, modifications, or claims, and the applicable federal laws. The government has the ability to seek a price adjustment based on the results of such audit. Any such audits have not had, and are not expected to have, a material impact on the financial position, operations, or cash flows of the Company.

Various legal actions, claims, assessments and other contingencies arising in the ordinary course of business are pending against the Company and certain of its subsidiaries. The Company will defend itself vigorously on all matters. These matters are subject to many uncertainties, and it is possible that some of these matters could ultimately be decided, resolved, or settled adversely to the Company. Although the Company is subject to various claims and legal actions that arise in the ordinary course of business, except as described below, the Company is not currently a party to any material legal proceedings or environmental claims. The Company records an accrual when it is probable a liability has been incurred and the amount of loss can be reasonably estimated. The Company does not believe any of these proceedings, individually or in the aggregate, would be expected to have a material effect on results of operations, cash flows or financial condition.

On April 23, 2014, the Company completed the sale of NASDI, LLC (“NASDI”) and Yankee Environmental Services, LLC (“Yankee”), which together comprised the Company’s historical demolition business, to a privately-owned demolition company. Under the terms of the agreement, the Company received cash of $5,309 and retained the right to receive additional proceeds based upon future collections of outstanding accounts receivable and work in process existing at the date of close. On January 14, 2015, the Company and its subsidiary, NASDI Holdings, LLC, brought an action in the Delaware Court of Chancery to enforce the terms of the Company's agreement to sell NASDI and Yankee. The Company seeks specific performance of the buyer’s obligation to collect and to remit the additional proceeds, and other related relief. Defendants have filed counterclaims alleging that the Company misrepresented the quality of its contracts and receivables prior to the sale. The Company denies defendants’ allegations. In addition, the Company has been granted a judgment in the amount of $21,934 based upon the buyer’s default of its obligations to indemnify the Company for losses resulting from failure to perform in accordance with terms of surety performance bond. On April 11, 2022, the Supreme Court of Delaware issued its decision denying that appeal and affirming the Chancery Court judgment. The Company continues to aggressively pursue collection from the buyer on outstanding amounts owed under the sale and the indemnification. An estimate of a range of potential gains or losses relating to these matters cannot reasonably be made.

On April 22, 2021, the U.S. Attorney’s Office for the Eastern District of Louisiana filed a bill of information against the Company charging the Company with a negligent discharge violation of the Clean Water Act (the "CWA") arising from a September 2016 oil spill. The spill occurred during the Company’s Cheniere Ronquille project and resulted in the discharge of around one hundred sixty barrels of crude oil in Bay Long, Louisiana. The Company cooperated with the U.S. Attorney’s Office and other relevant agencies in their investigation of the oil spill and on June 15, 2021, the Company pleaded guilty to the misdemeanor violation alleged in the bill of information and agreed to pay a fine of $1,000. In the first quarter of 2022, the Company entered into a settlement of a civil suit arising from the same matter which was primarily covered by its insurance policies. On June 14, 2022, the Company was sentenced in the criminal matter, and paid a fine of $1,000. The Company had previously deposited $2,000 into the registry of the court to pay any ordered restitution; however, the Company was not ordered to pay any restitution and the deposited funds, less the amount of the fine and administrative costs, were returned to the Company. The CWA provides that, upon an entity’s conviction of certain offenses, the entity is automatically disqualified from eligibility to receive certain federal contracts, if it will perform any part of the awarded contract at the facility giving rise to the conviction (called the “violating facility”). Accordingly, the Court’s entry of the Company’s conviction under the CWA resulted in the automatic disqualification of the Company’s eligibility to be awarded contracts at the violating facility, which the federal suspension and debarment officer (the “SDO”) determined to be the Company’s field office for the Cheniere Ronquille project, located at 28465 Hwy 23, Port Sulphur, Louisiana. The disqualification was imposed on June 23, 2022, and only applied to the Port Sulphur facility and not the Company as a whole. On the same day, June 23, 2022, the SDO issued a decision reinstating the Company’s Port Sulphur facility based on the SDO’s determination that the Company had addressed the causes of the CWA violation. This matter is now fully resolved and will not have any future impact on the Company’s business, financial condition or results of operations.

Lease obligations

The Company leases certain operating equipment and office facilities under long-term operating leases expiring at various dates through 2030. The equipment leases contain renewal or purchase options that specify prices at the then fair value upon the expiration of the lease terms. The leases also contain default provisions that are triggered by an acceleration of debt maturity under the terms of the Company’s Amended Credit Agreement, or, in certain instances, cross default to other equipment leases and certain lease arrangements require that the Company maintain certain financial ratios comparable to those required by its Amended Credit Agreement. Additionally, the leases typically contain provisions whereby the Company indemnifies the lessors for the tax treatment attributable to such leases based on the tax rules in place at lease inception. The tax indemnifications do not have a contractual dollar limit. To date, no lessors have asserted any claims against the Company under these tax indemnification provisions.