CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) shares in Millions, $ in Millions	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interests
Beginning Balance at Dec. 31, 2015	$ 2,747.9		$ 0.8	$ 1,143.0	$ 1,868.7	$ (282.6)	$ 18.0
Beginning Balance (in shares) at Dec. 31, 2015		0.8	84.9
Net income (loss)	207.9				206.3		1.6
Currency translation adjustment	(86.7)					(86.3)	(0.4)
Change in qualifying cash flow hedge, net of tax	1.3					1.3
Issuance of common stock for exercise of options, RSU vesting and employee stock purchases, net	44.8			44.8
Issuance of common stock for exercise of options, RSU vesting and employee stock purchases, net (in shares)			0.7
Repurchase and cancellation of treasury stock	(40.8)				(40.8)
Repurchase and cancellation of treasury stock (in shares)			(0.4)
Repurchase and cancellation of convertible preferred stock	(30.9)			(42.2)	11.3
Repurchase and cancellation of convertible preferred stock (in shares)		(0.1)
Preferred stock dividend	(39.4)				(39.4)
Stock compensation expense	20.5			20.5
Payments to noncontrolling interest	(8.2)			0.4			(8.6)
Ending Balance at Dec. 31, 2016	2,816.4		$ 0.8	1,166.5	2,006.1	(367.6)	10.6
Ending Balance (in shares) at Dec. 31, 2016		0.7	85.2
Net income (loss)	43.0				42.4		0.6
Currency translation adjustment	80.5					79.3	1.2
Change in qualifying cash flow hedge, net of tax	1.3					1.3
Issuance of common stock for exercise of options, RSU vesting and employee stock purchases, net	17.3		$ 0.1	17.2
Issuance of common stock for exercise of options, RSU vesting and employee stock purchases, net (in shares)			0.3
Repurchase and cancellation of convertible preferred stock	(34.2)			(51.5)	17.3
Repurchase and cancellation of convertible preferred stock (in shares)		0.0
Preferred stock dividend	(36.3)				(36.3)
Stock compensation expense	21.3			21.3
Reduction to noncontrolling interests due to additional ownership	(0.7)			(0.3)			(0.4)
Ending Balance at Dec. 31, 2017	2,908.6		$ 0.9	1,153.2	2,029.5	(287.0)	12.0
Ending Balance (in shares) at Dec. 31, 2017		0.7	85.5
Net income (loss)	(245.6)				(244.7)		(0.9)
Currency translation adjustment	(80.3)					(79.3)	(1.0)
Change in qualifying cash flow hedge, net of tax	1.0					1.0
Issuance of common stock for exercise of options, RSU vesting and employee stock purchases, net	19.4			19.4
Issuance of common stock for exercise of options, RSU vesting and employee stock purchases, net (in shares)			0.5
Repurchase and cancellation of convertible preferred stock	(17.2)			(34.1)	16.9
Repurchase and cancellation of convertible preferred stock (in shares)		(0.1)
Conversion of convertible preferred stock to common stock, (in shares)		(0.6)	4.7
Preferred stock dividend	(25.5)				(25.5)
Stock compensation expense	24.1			24.1
Payments to noncontrolling interest	(0.4)						(0.4)
Cumulative effect of new accounting standard (see Note 1)	13.0				13.0
Ending Balance at Dec. 31, 2018	$ 2,597.1		$ 0.9	$ 1,162.6	$ 1,789.2	$ (365.3)	$ 9.7
Ending Balance (in shares) at Dec. 31, 2018		0.0	90.7