Goodwill - Goodwill (Details) $ in Millions	6 Months Ended
Jun. 30, 2018 USD ($)
Goodwill [Roll Forward]
Balance as of December 31, 2017	$ 845.5
Additions	13.4
Foreign exchange and other adjustments	(2.2)
Balance as of June 30, 2018	856.7
Aviation segment
Goodwill [Roll Forward]
Balance as of December 31, 2017	326.9
Additions	0.0
Foreign exchange and other adjustments	(4.5)
Balance as of June 30, 2018	322.4
Land segment
Goodwill [Roll Forward]
Balance as of December 31, 2017	518.5
Additions	13.4
Foreign exchange and other adjustments	2.3
Balance as of June 30, 2018	$ 534.2

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266

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- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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