Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Series A Preferred stock	Series B Preferred stock	Common stock	Additional paid-in capital	Retained earnings (accumulated deficit)	Accumulated other comprehensive income (loss)	Treasury stock	Noncontrolling interest	Total
Balances at Dec. 31, 2012	$ 0.0	$ 0.1	$ 4.5	$ 9,730.9	$ 4,862.0	$ 640.3	$ (5,554.4)	$ 20.0	$ 9,703.4
Increase (decrease) in stockholders' equity
Common stock issued			0.1	125.7					125.8
Stock-based compensation and additional related tax benefits				72.7	(4.6)				68.1
Treasury stock acquired, common							(153.6)		(153.6)
Dividends to common stockholders					(288.4)				(288.4)
Dividends to preferred stockholders					(33.0)				(33.0)
Distributions to noncontrolling interest								(2.0)	(2.0)
Contributions from noncontrolling interest								115.3	115.3
Purchase of subsidiary shares from noncontrolling interest				1.4				(54.1)	(52.7)
Sale of subsidiary shares to noncontrolling interest				11.5				20.3	31.8
Adjustments to redemption amount of redeemable noncontrolling interest				(143.3)	(43.3)			(6.5)	(193.1)
Net income (loss) (excludes $4.9 million, $9.0 million and $13.6 million attributable to redeemable noncontrolling interest in 2015, 2014 and 2013 respectively)					912.7			9.8	922.5
Other comprehensive income (loss) (excludes $(18.8) million, $(5.3) million and $(4.8) million attributable to redeemable noncontrolling interest in 2015, 2014 and 2013 respectively)						(457.1)		(10.0)	(467.1)
Balances at Dec. 31, 2013	0.0	0.1	4.6	9,798.9	5,405.4	183.2	(5,708.0)	92.8	9,777.0
Increase (decrease) in stockholders' equity
Common stock issued				77.5					77.5
Stock-based compensation and additional related tax benefits				80.3	(6.1)				74.2
Treasury stock acquired, common							(222.7)		(222.7)
Dividends to common stockholders					(376.6)				(376.6)
Dividends to preferred stockholders					(33.0)				(33.0)
Distributions to noncontrolling interest								(23.9)	(23.9)
Contributions from noncontrolling interest								7.4	7.4
Purchase of subsidiary shares from noncontrolling interest				(2.0)				(45.6)	(47.6)
Adjustments to redemption amount of redeemable noncontrolling interest				(9.2)	(19.7)				(28.9)
Net income (loss) (excludes $4.9 million, $9.0 million and $13.6 million attributable to redeemable noncontrolling interest in 2015, 2014 and 2013 respectively)					1,144.1			23.3	1,167.4
Other comprehensive income (loss) (excludes $(18.8) million, $(5.3) million and $(4.8) million attributable to redeemable noncontrolling interest in 2015, 2014 and 2013 respectively)						(132.8)		(6.0)	(138.8)
Balances at Dec. 31, 2014	0.0	0.1	4.6	9,945.5	6,114.1	50.4	(5,930.7)	48.0	10,232.0
Increase (decrease) in stockholders' equity
Common stock issued			0.1	76.0					76.1
Stock-based compensation and additional related tax benefits				90.6	(6.5)			0.1	84.2
Treasury stock acquired, common							(300.6)		(300.6)
Dividends to common stockholders					(441.0)				(441.0)
Dividends to preferred stockholders					(16.5)				(16.5)
Preferred stock redemption		(0.1)		(541.7)	(8.2)				(550.0)
Distributions to noncontrolling interest								(15.4)	(15.4)
Contributions from noncontrolling interest								7.7	7.7
Purchase of subsidiary shares from noncontrolling interest				(19.0)		(10.3)		12.8	(16.5)
Adjustments to redemption amount of redeemable noncontrolling interest				(6.6)					(6.6)
Net income (loss) (excludes $4.9 million, $9.0 million and $13.6 million attributable to redeemable noncontrolling interest in 2015, 2014 and 2013 respectively)					1,234.0			14.3	1,248.3
Other comprehensive income (loss) (excludes $(18.8) million, $(5.3) million and $(4.8) million attributable to redeemable noncontrolling interest in 2015, 2014 and 2013 respectively)						(922.6)		(1.7)	(924.3)
Balances at Dec. 31, 2015	$ 0.0	$ 0.0	$ 4.7	$ 9,544.8	$ 6,875.9	$ (882.5)	$ (6,231.3)	$ 65.8	$ 9,377.4