Goodwill and Identifiable Intangible Assets - Goodwill (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Write-downs to goodwill or identifiable intangible assets	$ 0
Goodwill
Balance at the beginning of the period	675,800,000	$ 653,300,000
Acquisitions	173,300,000	39,400,000
Goodwill classified as held for sale		(5,900,000)
Adjustment of purchase price allocations	6,900,000
Foreign currency translation of non-USD functional currency subsidiary goodwill	(20,300,000)	(11,000,000)
Balance at the end of the period	835,800,000	675,800,000
Aviation segment
Goodwill
Balance at the beginning of the period	173,700,000	174,300,000
Acquisitions	95,600,000	1,700,000
Goodwill classified as held for sale		0
Adjustment of purchase price allocations	1,300,000
Foreign currency translation of non-USD functional currency subsidiary goodwill	(3,700,000)	(2,300,000)
Balance at the end of the period	266,800,000	173,700,000
Marine segment
Goodwill
Balance at the beginning of the period	71,400,000	73,100,000
Acquisitions	0	0
Goodwill classified as held for sale		0
Adjustment of purchase price allocations	100,000
Foreign currency translation of non-USD functional currency subsidiary goodwill	700,000	(1,700,000)
Balance at the end of the period	72,300,000	71,400,000
Land segment
Goodwill
Balance at the beginning of the period	430,700,000	405,900,000
Acquisitions	77,700,000	37,700,000
Goodwill classified as held for sale		(5,900,000)
Adjustment of purchase price allocations	5,500,000
Foreign currency translation of non-USD functional currency subsidiary goodwill	(17,300,000)	(7,000,000)
Balance at the end of the period	$ 496,700,000	$ 430,700,000