Consolidated Statement Of Shareholders' Equity (Deficit) - 3 months ended Mar. 31, 2017 - USD ($) shares in Millions, $ in Millions	Total	Preferred Stock [Member]	Common Stock [Member]	Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Preferred stock, issued, beginning balance at Dec. 31, 2016	0.0	0.0
Common stock, shares issued, beginning balance at Dec. 31, 2016	160.3		160.3
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period			0.6
Stock Issued During Period, Shares, Employee Stock Purchase Plans			0.0
Stock Repurchased During Period, Shares			(2.9)
Preferred stock, issued, ending balance at Mar. 31, 2017	0.0	0.0
Common stock, shares issued, ending balance at Mar. 31, 2017	158.0		158.0
Balance at Dec. 31, 2016	$ 1,045.5	$ 0.0	$ 1.6	$ 2,857.3	$ (1,673.8)	$ (139.6)
Shareholders' Equity (Deficit) [Roll Forward]
Equity-based compensation expense	10.6	0.0	0.0	10.6	0.0	0.0
Stock Option Exercises	4.4	0.0	0.0	4.4	0.0	0.0
Stock Issued During Period, Value, Employee Stock Purchase Plan	2.1	0.0	0.0	2.1	0.0	0.0
Dividends	(25.3)	0.0	0.0	0.2	(25.5)	0.0
Incentive compensation plan units withheld for taxes	(18.3)				(18.3)
Net income (loss)	57.6	0.0	0.0	0.0	57.6	0.0
Stock Repurchased and Retired During Period, Value	(175.4)	0.0	0.0	0.0	(175.4)	0.0
Foreign currency translation adjustment	6.5	0.0	0.0	0.0	0.0	6.5
Balance at Mar. 31, 2017	907.3	$ 0.0	$ 1.6	$ 2,874.6	(1,835.4)	(133.5)
Shareholders' Equity (Deficit) [Roll Forward]
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	$ (0.4)				$ 0.0	$ (0.4)