Condensed Consolidated Statements of Redeemable Equity and Stockholder Equity (Unaudited) (USD $) In Millions, unless otherwise specified	Total	Redeemable Equity	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Stockholder Equity
Beginning balance, stockholder's equity at Dec. 31, 2014	$ 1,339.7		$ 1.3	$ 1,716.3	$ (148.0)	$ (229.9)	$ 1,339.7
Beginning balance, redeemable equity at Dec. 31, 2014	51.4	51.4
Beginning balance, stockholder's equity, shares at Dec. 31, 2014			131.4
Increase (decrease) in redeemable equity:
Reclassifications to state redeemable equity at redemption value		5.7
Increase (decrease) in stockholder equity:
Share-based compensation expense				1.1			1.1
Reclassifications to state redeemable equity at redemption value				(5.7)			(5.7)
Net income	71.5				71.5		71.5
Other comprehensive loss	(165.2)					(165.2)	(165.2)
Ending balance, stockholder's equity at Mar. 31, 2015	1,241.4		1.3	1,711.7	(76.5)	(395.1)	1,241.4
Ending balance, redeemable equity at Mar. 31, 2015	$ 57.1	$ 57.1
Ending balance, stockholder's equity, shares at Mar. 31, 2015			131.4