Consolidated Statements Of Stockholders' Equity - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock	Non-controlling Minority Interests
Beginning balance at Dec. 31, 2014	$ 9,052.6	$ 0.0	$ 2.0	$ 8,603.6	$ 1,604.8	$ (133.9)	$ (1,018.5)	$ (5.4)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1,034.0				1,034.1			(0.1)
Other comprehensive income (loss), net of tax	(8.2)					(8.2)
Dividends paid	(114.9)				(114.9)
Amortization of restricted stock, stock option, and performance shares and other expenses	70.0			93.4			(23.4)
Repurchase of common stock	(531.8)						(531.8)
Issuance of common stock — acquisition	1,462.0			45.6			1,416.4
Employee stock purchase plan	2.0			2.0
Distribution of earnings and capital	(20.5)			(26.5)				6.0
Ending balance at Dec. 31, 2015	10,945.2	0.0	2.0	8,718.1	2,524.0	(142.1)	(157.3)	0.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(848.0)				(848.0)
Other comprehensive income (loss), net of tax	2.0					2.0
Dividends paid	(123.0)				(123.0)
Amortization of restricted stock, stock option, and performance shares and other expenses	24.7		0.1	45.4			(20.8)
Employee stock purchase plan	2.3			2.3
Other	(0.1)							(0.1)
Ending balance at Dec. 31, 2016	10,003.1	0.0	2.1	8,765.8	1,553.0	(140.1)	(178.1)	0.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of ASU 2016-09				1.0	(1.0)
Beginning balance, adjusted	10,003.1	0.0	2.1	8,766.8	1,552.0	(140.1)	(178.1)	0.4
Net income (loss)	468.2				468.2
Other comprehensive income (loss), net of tax	53.6					53.6
Dividends paid	(113.7)				(113.7)
Issuance of preferred stock	318.0	325.0		(7.0)
Share repurchases	(3,431.9)			(9.6)			(3,422.3)
Amortization of restricted stock, stock option, and performance shares and other expenses	20.3			45.1			(24.8)
Employee stock purchase plan	2.8			2.8
Other	(0.4)							(0.4)
Ending balance at Dec. 31, 2017	$ 7,320.0	$ 325.0	$ 2.1	$ 8,798.1	$ 1,906.5	$ (86.5)	$ (3,625.2)	$ 0.0