Consolidated Statements of Stockholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock [Member]	Parent [Member]	Noncontrolling Interest [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 4,311.1	$ 1.6	$ 534.6	$ 3,497.3	$ (113.5)	$ (1.5)	$ 3,918.5	$ 392.6
Common Stock, Shares, Issued		(152.2)				(0.1)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	713.6			702.5			702.5	11.1
Other Comprehensive Income (Loss), Net of Tax	11.3				8.7		8.7	2.6
Dividends, Common Stock, Cash	(75.8)			(75.8)			(75.8)
Share-based Payment Arrangement, Expense	24.6		24.6				24.6
Treasury Stock, Value, Acquired, Cost Method	(85.4)		0.0			$ (85.4)	(85.4)
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		1.7				(0.7)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	7.9		(10.6)			$ 18.5	7.9
Stock Issued During Period, Value, Stock Options Exercised	0.2		0.2				0.2
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(48.7)						0.0	(48.7)
Treasury Stock, Shares, Retired		3.5				3.5
Treasury Stock, Retired, Cost Method, Amount	0.0		(103.8)	0.0		$ (103.8)	0.0
Stock Issued During Period, Shares, Acquisitions		0.5
Stock Issued During Period, Value, Acquisitions	14.7		14.7				14.7
Stockholders' Equity, Other	0.3		1.6	(0.6)			1.0	(0.7)
Treasury Stock, Shares, Acquired						(2.8)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	4,858.0	$ 1.6	482.5	4,123.4	(104.8)	$ (1.6)	4,501.1	356.9
Common Stock, Shares, Issued		(150.9)				(0.1)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	163.1			159.3			159.3	3.8
Other Comprehensive Income (Loss), Net of Tax	(13.2)				(14.6)		(14.6)	1.4
Dividends, Common Stock, Cash	(75.9)			(75.9)			(75.9)
Share-based Payment Arrangement, Expense	29.3		29.3				29.3
Treasury Stock, Value, Acquired, Cost Method	(500.1)		75.9	(145.9)		$ (430.1)	(500.1)
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		0.2				(0.6)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	4.3		(15.1)			$ 19.4	4.3
Stock Issued During Period, Value, Stock Options Exercised	0.3		0.3				0.3
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(10.9)						0.0	(10.9)
Treasury Stock, Shares, Retired		17.8				17.8
Treasury Stock, Retired, Cost Method, Amount	0.0	$ (0.2)	(449.3)	0.0		$ (449.5)	0.0
CumulativeEffectofNewAccountingPrincipleinPeriodofAdoption(Duration)	0.0			18.7	(18.7)		0.0
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt	(152.9)		(152.9)				(152.9)
Stockholders' Equity Note, Spinoff Transaction	(1,732.2)			(1,753.5)	21.3		(1,732.2)
Stockholders' Equity, Other	0.8	(0.1)	0.3	0.0		$ 0.6	0.8
Treasury Stock, Shares, Acquired						(17.2)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	2,562.0	$ 1.3	1.2	2,326.1	(116.8)	$ (1.0)	2,210.8	351.2
Common Stock, Shares, Issued		(133.3)				(0.1)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	136.1			137.6			137.6	(1.5)
Other Comprehensive Income (Loss), Net of Tax	(35.0)				(36.3)		(36.3)	1.3
Dividends, Common Stock, Cash	(88.2)			(88.2)			(88.2)
Share-based Payment Arrangement, Expense	29.2		29.2				29.2
Treasury Stock, Value, Acquired, Cost Method	(224.7)		70.0	0.0		$ (294.7)	(224.7)
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		0.7				(0.6)
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures	8.5		(2.8)			$ 11.3	8.5
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(2.2)						0.0	(2.2)
Treasury Stock, Shares, Retired		14.3				14.3
Treasury Stock, Retired, Cost Method, Amount	0.0	$ (0.1)	(103.2)	(202.8)		$ (306.1)	0.0
CumulativeEffectofNewAccountingPrincipleinPeriodofAdoption(Duration)	13.7			13.7	0.0		13.7
Stockholders' Equity, Other	(3.5)		$ 0.0	(3.5)			(3.5)	0.0
Treasury Stock, Shares, Acquired			(2.6)			(13.7)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 2,378.9	$ 1.2	$ 0.0	$ 2,182.9	$ (153.1)	$ (0.9)	$ 2,030.1	$ 348.8
Common Stock, Shares, Issued		(119.7)				(0.1)