Restructuring (Details) $ in Millions	9 Months Ended
	Sep. 30, 2018 USD ($)
Restructuring Reserve [Roll Forward]
Balance as of December 31, 2017	$ 32.0
Employee-related costs incurred	12.2
Paid during the period	(18.2)
Restructuring charges as of September 30, 2018	26.1
Operating Segments | Aviation segment
Restructuring Reserve [Roll Forward]
Balance as of December 31, 2017	0.7
Employee-related costs incurred	1.6
Paid during the period	(0.5)
Restructuring charges as of September 30, 2018	1.8
Operating Segments | Land segment
Restructuring Reserve [Roll Forward]
Balance as of December 31, 2017	25.0
Employee-related costs incurred	5.6
Paid during the period	(12.5)
Restructuring charges as of September 30, 2018	18.1
Operating Segments | Marine segment
Restructuring Reserve [Roll Forward]
Balance as of December 31, 2017	1.3
Employee-related costs incurred	1.4
Paid during the period	(1.0)
Restructuring charges as of September 30, 2018	1.8
Corporate
Restructuring Reserve [Roll Forward]
Balance as of December 31, 2017	5.0
Employee-related costs incurred	3.6
Paid during the period	(4.2)
Restructuring charges as of September 30, 2018	$ 4.4