CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (DEFICIT) - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock	Noncontrolling Interest
Shareholders' Equity, Beginning Balance at Dec. 31, 2016	$ (836.2)	$ 188.8	$ 2,273.9	$ 2,322.2	$ (1,033.2)	$ (4,599.7)	$ 11.8
Balance (in shares) at Dec. 31, 2016		754.9				317.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	20.0			22.0			(2.0)
Other comprehensive income (loss)	107.7				107.0		0.7
Dividends accrued - Series C convertible preferred stock	(23.1)			(23.1)
Exercise/ vesting/ expense of share-based compensation	24.3	$ 1.0	17.3	(0.8)		$ 6.8
Exercise/ vesting/ expense of share-based compensation (in shares)		3.8				(0.5)
Repurchase of common stock	(7.2)	$ (0.1)				$ (7.1)
Repurchase of common stock (in shares)						1.6
Purchases and sales of noncontrolling interests, net of dividends paid	(0.2)						(0.2)
Shareholders' Equity, Ending Balance at Dec. 31, 2017	(714.7)	$ 189.7	2,291.2	2,320.3	(926.2)	$ (4,600.0)	10.3
Balance (in shares) at Dec. 31, 2017		758.7				318.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(21.8)			(19.5)			(2.3)
Other comprehensive income (loss)	(104.4)				(104.2)		(0.2)
Dividends accrued - Series C convertible preferred stock	(24.3)			(24.3)
Exercise/ vesting/ expense of share-based compensation	12.8	$ 0.7	12.4	(1.1)		$ 0.8
Exercise/ vesting/ expense of share-based compensation (in shares)		3.1				(0.1)
Repurchase of common stock	(3.2)	$ (0.1)				$ (3.1)
Repurchase of common stock (in shares)						1.1
Purchases and sales of noncontrolling interests, net of dividends paid	(0.1)						(0.1)
Shareholders' Equity, Ending Balance at Dec. 31, 2018	(896.8)	$ 190.3	2,303.6	2,234.3	(1,030.4)	$ (4,602.3)	7.7
Balance (in shares) at Dec. 31, 2018		761.8				319.4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(1.3)			(0.3)			(1.0)
Other comprehensive income (loss)	(9.4)				(9.6)		0.2
Dividends accrued - Series C convertible preferred stock	(25.5)			(25.5)
Dividends accrued- common stock	(8.7)			(8.7)
Exercise/ vesting/ expense of share-based compensation	28.5	$ 2.6	25.9
Exercise/ vesting/ expense of share-based compensation (in shares)		9.9
Repurchase of common stock	(9.6)	$ (0.3)	(8.3)			$ (1.0)
Repurchase of common stock (in shares)		1.7				0.5
Remeasurement of Series C convertible preferred stock	(60.9)			(60.9)
Purchases and sales of noncontrolling interests, net of dividends paid	(0.1)						(0.1)
Shareholders' Equity, Ending Balance at Dec. 31, 2019	$ (983.8)	$ 192.6	$ 2,321.2	$ 2,138.9	$ (1,040.0)	$ (4,603.3)	$ 6.8
Balance (in shares) at Dec. 31, 2019		770.0				319.9