CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY AND NONCONTROLLING INTERESTS - USD ($) $ in Millions	Total	Common stock issued, Class A	Common stock issued, Class B	Exchangeable shares issued, Class A	Exchangeable shares issued, Class B	Paid-in capital	Retained earnings	Accumulated other comprehensive income (loss)	Common stock held in treasury, Class B	Noncontrolling interest
Balance at Dec. 31, 2017	$ 13,187.3	$ 0.0	$ 2.0	$ 107.7	$ 553.2	$ 6,688.5	$ 6,958.4	$ (860.0)	$ (471.4)	$ 208.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exchange of shares	0.0			(4.5)	4.4	0.1
Shares issued under equity compensation plan	2.8					2.8
Amortization of share-based compensation	42.2					42.2
Payments to Acquire Interest in Joint Venture	44.3					39.4				4.9
Purchase of noncontrolling Interest	(0.2)					0.1				(0.3)
Net income (loss) including noncontrolling interests	1,134.6						1,116.5			18.1
Other comprehensive income (loss), net of tax	(292.0)							(290.0)		(2.0)
Initial Application Period Cumulative Effect Transition for Accounting Standards Update 2014-09	(27.8)						(27.8)
Contributions from noncontrolling interests	21.6									21.6
Distributions and dividends to noncontrolling interests	(22.8)									(22.8)
Dividends declared and paid	$ (354.2)						(354.2)
Common Stock, Dividends, Per Share, Declared	$ 1.64
Balance at Dec. 31, 2018	$ 13,735.8	0.0	2.0	103.2	557.6	6,773.1	7,692.9	(1,150.0)	(471.4)	228.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exchange of shares	0.0			(0.7)	0.2	0.5
Shares issued under equity compensation plan	(8.3)		0.1			(8.4)
Amortization of share-based compensation	8.3					8.3
Purchase of noncontrolling Interest	0.6					0.1				0.5
Noncontrolling Interest, Decrease from Deconsolidation	(1.7)									(1.7)
Net income (loss) including noncontrolling interests	246.2						241.7			4.5
Other comprehensive income (loss), net of tax	63.2							62.6		0.6
Initial Application Period Cumulative Effect Transition for Accounting Standards Update 2016-02	32.0						32.0
Increase in retained earnings due to reclassification of stranded tax effects	0.0						74.8	(74.8)
Contributions from noncontrolling interests	34.1									34.1
Distributions and dividends to noncontrolling interests	(12.7)									(12.7)
Dividends declared and paid	$ (424.4)						(424.4)
Common Stock, Dividends, Per Share, Declared	$ 1.96
Balance at Dec. 31, 2019	$ 13,673.1	0.0	2.1	102.5	557.8	6,773.6	7,617.0	(1,162.2)	(471.4)	253.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exchange of shares	0.0			(0.2)	(140.0)	140.2
Shares issued under equity compensation plan	(0.5)		0.0			(0.5)
Amortization of share-based compensation	24.2					24.2
Purchase of noncontrolling Interest	(0.2)					0.3				(0.5)
Net income (loss) including noncontrolling interests	(945.7)						(949.0)			3.3
Other comprehensive income (loss), net of tax	(3.4)							(5.6)		2.2
Contributions from noncontrolling interests	16.3									16.3
Distributions and dividends to noncontrolling interests	(18.7)									(18.7)
Dividends declared and paid	$ (123.8)						(123.8)
Common Stock, Dividends, Per Share, Declared	$ 0.57
Balance at Dec. 31, 2020	$ 12,621.3	$ 0.0	$ 2.1	$ 102.3	$ 417.8	$ 6,937.8	$ 6,544.2	$ (1,167.8)	$ (471.4)	$ 256.3