Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes.

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Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

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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.

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The number of businesses acquired by the entity during the period.

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Acquisitions and Divestitures - 2017 Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) acquisition	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Business Acquisition [Line Items]
Goodwill	$ 845.5	$ 843.7	$ 852.7
Aviation segment
Business Acquisition [Line Items]
Goodwill	326.9	323.6	322.9
Land segment
Business Acquisition [Line Items]
Goodwill	$ 518.5	$ 520.1	$ 529.7
Acquisitions 2017
Business Acquisition [Line Items]
Number of business acquired \| acquisition	5
Goodwill	$ 63.5
Goodwill anticipated to be deductible for tax purposes	29.5
Acquisitions 2017 \| Customer relationships
Business Acquisition [Line Items]
Identifiable intangible assets	$ 41.7
Weighted average amortizable lives of identifiable intangible assets	8 years
Acquisitions 2017 \| Aviation segment
Business Acquisition [Line Items]
Goodwill	$ 51.3
Acquisitions 2017 \| Land segment
Business Acquisition [Line Items]
Goodwill	$ 12.2