Number of airports to be acquired through a definitive agreement.

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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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Value received from shareholders in common stock-related transactions that are in excess of par value or stated value and amounts received from other stock-related transactions. Includes only common stock transactions (excludes preferred stock transactions). May be called contributed capital, capital in excess of par, capital surplus, or paid-in capital.

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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 consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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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 equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

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The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

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Amount of increase in noncontrolling interest from a business combination.

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

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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Acquisitions - Narrative (Details) $ in Millions		3 Months Ended		9 Months Ended
Acquisitions - Narrative (Details) $ in Millions	Jun. 23, 2016 USD ($)	Mar. 31, 2017 acquisition	Mar. 31, 2016 airport	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($) acquisition	Dec. 31, 2016 USD ($)
Acquisitions
Goodwill				$ 901.1		$ 835.8
Previous percentage ownership of noncontrolling owners	49.00%				49.00%
Capital in excess of par value				349.3		399.9
Land segment
Acquisitions
Goodwill				506.6		$ 496.7
Acquisitions 2017
Acquisitions
Number of businesses acquired \| acquisition		2
Goodwill				46.4
Goodwill anticipated to be deductible for tax purposes				22.4
Estimated purchase price				91.9
Acquisitions 2017 \| Customer relationships
Acquisitions
Identifiable intangible assets				$ 33.4
Weighted average amortizable lives of identifiable intangible assets				9 years 10 months 24 days
Acquisitions 2016
Acquisitions
Goodwill				$ 73.4
Goodwill anticipated to be deductible for tax purposes				72.0
Estimated purchase price					$ 264.0
Acquisitions 2016 \| Trademark/trade name rights
Acquisitions
Identifiable intangible assets				9.5
Acquisitions 2016 \| Land segment
Acquisitions
Number of businesses acquired \| acquisition					5
Acquisitions 2016 \| Customer relationships
Acquisitions
Identifiable intangible assets				$ 79.7
Weighted average amortizable lives of identifiable intangible assets				5 years 4 months 24 days
Acquisitions 2016 \| Other identifiable assets
Acquisitions
Identifiable intangible assets				$ 3.9
Weighted average amortizable lives of identifiable intangible assets				2 years
Aviation fueling operations of certain ExxonMobil affiliates
Acquisitions
Number of airports to be acquired (more than) \| airport			80
Tobras
Acquisitions
Estimated purchase price	$ 3.7
Previous percentage of ownership of parent	51.00%
Capital in excess of par value	$ 10.9
Cash paid for acquisition of businesses	3.7
Increase in noncontrolling interest equity	$ 7.2