Revenue - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) provider	Dec. 31, 2018 USD ($)
Construction
Revenue from External Customer [Line Items]
Change in contract assets costs in excess of billings, new commercial contracts	$ 26.2
Change in contract assets costs in excess of billings, transfer to receivables	41.3
Change in contract liabilities costs in excess of billings, new commercial contracts	49.3
Change in contract liabilities costs in excess of billings, transfer to receivables	60.5
Remaining commitment obligations, amount	36.0
Energy
Revenue from External Customer [Line Items]
Revenue after customer rebates tax credits	$ 10.6	$ 2.6
Telecommunication - Maintenance | Marine Services
Revenue from External Customer [Line Items]
Number of global telecommunications providers | provider	60
Telecommunication - Maintenance | Marine Services | Minimum
Revenue from External Customer [Line Items]
Term of contract	5 years
Telecommunication - Maintenance | Marine Services | Maximum
Revenue from External Customer [Line Items]
Term of contract	7 years
Telecommunication - Installation | Marine Services | Minimum
Revenue from External Customer [Line Items]
Term of contract	1 year
Telecommunication - Installation | Marine Services | Maximum
Revenue from External Customer [Line Items]
Term of contract	5 years