Intangible Franchise Rights and Goodwill - Goodwill by Reportable Segment (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
BALANCE	$ 913,034
Additions through acquisitions	47,765
Purchase price allocation adjustments	12
Disposals and assets held for sale	(9,981)
Currency translation	(4,995)
BALANCE	945,835
Accumulated goodwill impairment	97,800	$ 97,800
U.S.
Goodwill [Roll Forward]
BALANCE	835,267
Additions through acquisitions	14,199
Purchase price allocation adjustments	12
Disposals and assets held for sale	(9,981)
Currency translation	0
BALANCE	839,497
U.K.
Goodwill [Roll Forward]
BALANCE	65,034
Additions through acquisitions	29,281
Purchase price allocation adjustments	0
Disposals and assets held for sale	0
Currency translation	(2,692)
BALANCE	91,623
Brazil
Goodwill [Roll Forward]
BALANCE	12,733
Additions through acquisitions	4,285
Purchase price allocation adjustments	0
Disposals and assets held for sale	0
Currency translation	(2,303)
BALANCE	$ 14,715

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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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.

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Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of divestiture 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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