Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Capital in Excess of Par Value	Accumulated Deficit	Accumulated Other Comprehensive Loss	Treasury Stock	Noncontrolling Interests
Balance at beginning of period at Dec. 31, 2014	$ 619.5	$ 1.0	$ 2,810.5	$ (1,879.1)	$ (0.5)	$ (458.7)	$ 146.3
Balance at beginning of period, Shares at Dec. 31, 2014		87.8
Net income	85.4			85.4
Net income attributable to nonredeemable noncontrolling interest	27.4						27.4
Net income, including portion attributable to nonredeemable noncontrolling interest, total	112.8
Conversion of preferred stock, shares		3.3
Conversion of preferred stock	93.2		93.2
Receipt of treasury stock	(16.6)					(16.6)
Receipt of treasury stock, Shares		(0.5)
Dividends declared on common stock	(38.0)		(38.0)
Dividends declared on convertible perpetual preferred stock	(1.6)		(1.6)
Stock-based compensation	14.9		14.9
Stock options exercised	2.0		5.6			(3.6)
Stock options exercised, Shares		0.2
Distributions declared	(23.4)						(23.4)
Capital contributions from consolidated affiliates	8.6						8.6
Fair value adjustments to redeemable noncontrolling interests, net of tax	(6.8)		(6.8)
Other	0.1	$ 0.1	0.6	(0.2)	0.2	(0.5)	(0.1)
Other, Shares		0.7
Balance at end of period at Jun. 30, 2015	764.7	$ 1.1	2,878.4	(1,793.9)	(0.3)	(479.4)	158.8
Balance at end of period, Shares at Jun. 30, 2015		91.5
Balance at beginning of period at Dec. 31, 2015	779.3	$ 1.1	2,834.9	(1,696.0)	(1.2)	(527.4)	167.9
Balance at beginning of period, Shares at Dec. 31, 2015		90.1
Net income	120.6			120.6
Net income attributable to nonredeemable noncontrolling interest	29.8						29.8
Net income, including portion attributable to nonredeemable noncontrolling interest, total	150.4
Receipt of treasury stock	(9.9)					(9.9)
Receipt of treasury stock, Shares		(0.4)
Dividends declared on common stock	(41.7)		(41.7)
Stock-based compensation	11.5		11.5
Stock options exercised	0.7		5.4			(4.7)
Stock options exercised, Shares		0.2
Distributions declared	(29.9)						(29.9)
Capital contributions from consolidated affiliates	7.6						7.6
Fair value adjustments to redeemable noncontrolling interests, net of tax	2.8		2.8
Repurchases of common stock	(24.1)					(24.1)
Repurchases of common stock, Shares		(0.7)
Other	2.7		1.7		0.3	(0.6)	1.3
Other, Shares		0.6
Balance at end of period at Jun. 30, 2016	$ 849.4	$ 1.1	$ 2,814.6	$ (1,575.4)	$ (0.9)	$ (566.7)	$ 176.7
Balance at end of period, Shares at Jun. 30, 2016		89.8