Revisions in Estimates - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Change In Accounting Estimate [Line Items]
Change in accounting estimate amount considered significant to individual project gross profit	$ 5.0	$ 5.0
Net Estimate Change [Member] \| Transportation [Member]
Change In Accounting Estimate [Line Items]
Increase (decrease) on project profitability	$ (5.7)	$ (5.3)

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.

No definition available.

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