Property, Plant, and Equipment, net - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 52.3	$ 46.6
Depreciation expense with cost of revenue	9.1	7.0
Marine Services
Property, Plant and Equipment [Line Items]
Impairment charges	0.6
Cable-ships and Submersibles
Property, Plant and Equipment [Line Items]
Net book value of equipment under capital leases	$ 35.1	40.0
ANG
Property, Plant and Equipment [Line Items]
Impairment charges		0.7
ANG | Station Performance
Property, Plant and Equipment [Line Items]
Impairment charges		0.4
ANG | Station Project
Property, Plant and Equipment [Line Items]
Impairment charges		$ 0.3