Summary of Significant Accounting Principles - Property and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment
Assets classified as held-for-sale	$ 0.0	$ 0.0	$ 1.0	$ 6.4
Equipment improvement | Minimum
Property, Plant and Equipment
Property and equipment useful life	3 years
Equipment improvement | Maximum
Property, Plant and Equipment
Property and equipment useful life	7 years
Automobiles and trucks | Minimum
Property, Plant and Equipment
Property and equipment useful life	3 years
Automobiles and trucks | Maximum
Property, Plant and Equipment
Property and equipment useful life	5 years
Building and improvements | Minimum
Property, Plant and Equipment
Property and equipment useful life	5 years
Building and improvements | Maximum
Property, Plant and Equipment
Property and equipment useful life	30 years
Construction equipment | Minimum
Property, Plant and Equipment
Property and equipment useful life	3 years
Construction equipment | Maximum
Property, Plant and Equipment
Property and equipment useful life	15 years
Vessels and other equipment | Minimum
Property, Plant and Equipment
Property and equipment useful life	1 year
Vessels and other equipment | Maximum
Property, Plant and Equipment
Property and equipment useful life	15 years
Office equipment | Minimum
Property, Plant and Equipment
Property and equipment useful life	1 year
Office equipment | Maximum
Property, Plant and Equipment
Property and equipment useful life	5 years
Dry-docking capitalized costs | Minimum
Property, Plant and Equipment
Property and equipment useful life	3 years
Dry-docking capitalized costs | Maximum
Property, Plant and Equipment
Property and equipment useful life	15 years