Revenue Recognition - Pro Forma adjustments to income statement (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Revenues	$ 1,375.3	$ 1,208.6	$ 3,972.5	$ 3,341.9
Operating costs and expenses:
Cost of sales	469.9	493.3	1,347.9	1,376.9
Franchise and property expenses	107.6	118.5	314.4	343.2
Selling, general and administrative expenses	298.3	100.1	917.2	318.7
(Income) loss from equity method investments	(3.8)	(4.1)	(16.9)	(8.9)
Other operating expenses (income), net	26.1	21.5	9.4	82.1
Total operating costs and expenses	898.1	729.3	2,572.0	2,112.0
Income from operations	477.2	479.3	1,400.5	1,229.9
Interest expense, net	134.9	136.0	404.8	375.4
Income before income taxes	342.3	285.1	995.7	775.9
Income tax expense	92.5	38.3	152.9	119.0
Net income	249.8	246.8	842.8	656.9
Net income attributable to noncontrolling interests	116.2	87.9	393.8	223.3
Net income attributable to common shareholders	$ 133.6	$ 91.4	$ 449.0	$ 231.1
Earnings per common share:
Basic (in usd per share)	$ 0.53	$ 0.39	$ 1.81	$ 0.98
Diluted (in usd per share)	$ 0.53	$ 0.37	$ 1.78	$ 0.95
Total Adjustments
Operating costs and expenses:
Franchise and property expenses	$ (0.2)		$ (0.4)
Interest expense, net	(0.7)		0.5
Amounts Under Previous Standards
Revenues:
Revenues	1,182.0		3,398.1
Operating costs and expenses:
Cost of sales	469.9		1,347.9
Franchise and property expenses	107.4		314.0
Selling, general and administrative expenses	100.5		328.8
(Income) loss from equity method investments	(4.9)		(21.6)
Other operating expenses (income), net	26.2		9.5
Total operating costs and expenses	699.1		1,978.6
Income from operations	482.9		1,419.5
Interest expense, net	134.2		405.3
Income before income taxes	348.7		1,014.2
Income tax expense	93.4		157.0
Net income	255.3		857.2
Net income attributable to noncontrolling interests	118.8		400.6
Net income attributable to common shareholders	$ 136.5		$ 456.6
Earnings per common share:
Basic (in usd per share)	$ 0.54		$ 1.84
Diluted (in usd per share)	$ 0.54		$ 1.81
Accounting Standards Update 2014-09 | Total Adjustments
Revenues:
Revenues	$ (193.3)		$ (574.4)
Operating costs and expenses:
Cost of sales	0.0		0.0
Franchise and property expenses	(0.2)		(0.4)
Selling, general and administrative expenses	(197.8)		(588.4)
(Income) loss from equity method investments	(1.1)		(4.7)
Other operating expenses (income), net	0.1		0.1
Total operating costs and expenses	(199.0)		(593.4)
Income from operations	5.7		19.0
Interest expense, net	(0.7)		0.5
Income before income taxes	6.4		18.5
Income tax expense	0.9		4.1
Net income	5.5		14.4
Net income attributable to noncontrolling interests	2.6		6.8
Net income attributable to common shareholders	2.9		7.6
Sales
Revenues:
Sales	609.1	$ 631.6	1,743.1	$ 1,784.1
Sales | Amounts Under Previous Standards
Revenues:
Sales	609.1		1,743.1
Sales | Accounting Standards Update 2014-09 | Total Adjustments
Revenues:
Sales	0.0		0.0
Franchise and property revenues
Revenues:
Revenues	766.2	$ 577.0	2,229.4	$ 1,557.8
Franchise and property revenues | Total Adjustments
Revenues:
Revenues	9.0		14.0
Operating costs and expenses:
Income tax expense	1.7		4.1
Franchise and property revenues | Amounts Under Previous Standards
Revenues:
Revenues	572.9		1,655.0
Franchise and property revenues | Accounting Standards Update 2014-09 | Total Adjustments
Revenues:
Revenues	$ (193.3)		$ (574.4)