Number of claimants paid in a legal action.

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The number of individuals filing claims in a legal matter.

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No definition available.

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Number of crew deaths resulting from the dredge fire.

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No definition available.

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The number of crewmembers on the dredge.

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No definition available.

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The number of gallons of oil, diesel fuel, and contaminated water discharged during the fire.

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Number of lawsuits filed against the entity.

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No definition available.

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Amount of loss contingency liability expected to be resolved within one year or the normal operating cycle, if longer.

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Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

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Amount, after allowance for credit loss, of financing receivable, classified as current. Includes, but is not limited to, notes and loan receivable.

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Amount, after allowance for credit loss, of financing receivable, classified as noncurrent.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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The amount of cash paid for the settlement of litigation or for other legal issues during the period.

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Cash received for the settlement of litigation during the current period.

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Disclosure of the unamortized amount of the discount on the note or receivable which is deducted from the face amount of the receivable or loan. The discount or premium is the difference between the present value and the face amount.

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Commitments and Contingencies - Narrative (Details) $ in Millions		3 Months Ended	9 Months Ended
	Aug. 21, 2020 item gal	Mar. 31, 2018 USD ($)	Sep. 30, 2021 USD ($) claim lawsuit
Settled Litigation
Other Commitments [Line Items]
Legal settlement		$ 5.5
Notes receivable, current			$ 0.8
Notes receivables, noncurrent			1.3
Receivable, unamortized discount			$ 0.1
Waymon L Boyd Dredge Fire
Other Commitments [Line Items]
Number of crew deaths \| item	5
Number of gallons of oil, diesel fuel, and contaminated water discharged \| gal	18,000
Number of crewmembers \| item	18
Waymon L Boyd Dredge Fire \| Pending Litigation
Other Commitments [Line Items]
Number of lawsuits filed \| lawsuit			8
Number of claimants \| claim			13
Estimated costs recognized			$ 102.1
Accrued loss contingency			62.4
Payments to claimants			$ 39.6
Number of crewmember claimants paid \| claim			12