Consolidated Statements of Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Retained Earnings	Treasury Stock	Performance Shares Common Stock
Balance at beginning of year (As Reported) at Dec. 31, 2014					$ 486.9
Balance at beginning of year (Restatement Adjustment)					20.8
Balance at beginning of year at Dec. 31, 2014		$ 1.4	$ 539.7	$ (130.5)	507.7	$ (73.4)
Balance (in shares) at Dec. 31, 2014		33,885,967
Increase (Decrease) in Stockholders' Equity
Stock options exercised and issuance of other stock awards			2.3			1.8
Stock options exercised (in shares)		116,154
Restricted stock, net (in shares)		90,496
Performance shares issued (in shares)							61,673
Windfall tax benefit on stock options exercised			1.5
Stock-based compensation			14.5
Other comprehensive loss	$ (77.3)			(77.3)
Net income (loss)	65.5				65.5
Cash dividends					(10.9)
Balance (in shares) at Dec. 31, 2015		34,154,290
Balance at end of year (As Reported) at Dec. 31, 2015					539.5
Balance at end of year (Restatement Adjustment)					22.8
Balance at end of year at Dec. 31, 2015	842.3	$ 1.4	558.0	(207.8)	562.3	(71.6)
Increase (Decrease) in Stockholders' Equity
Stock options exercised and issuance of other stock awards			0.3			8.7
Distribution of Spun-off subsidiary				68.0	60.8
Stock options exercised (in shares)		687,619
Restricted stock, net (in shares)		(9,112)
Performance shares issued (in shares)							127,506
Stock-based compensation			9.3
Other comprehensive loss	(23.1)			(23.1)
Net income (loss)	(375.8)			68.0	(375.8)
Balance (in shares) at Dec. 31, 2016		34,960,303
Balance at end of year (As Reported) at Dec. 31, 2016					247.3
Balance at end of year at Dec. 31, 2016	590.5	$ 1.4	567.6	(162.9)	247.3	(62.9)
Increase (Decrease) in Stockholders' Equity
Stock options exercised and issuance of other stock awards			2.0			3.1
Stock options exercised (in shares)		262,118
Restricted stock, net (in shares)		23,566
Performance shares issued (in shares)							27,877
Stock-based compensation			7.0
Other comprehensive loss	65.5			65.5
Net income (loss)	9.4				9.4
Balance (in shares) at Dec. 31, 2017		35,273,864
Balance at end of year at Dec. 31, 2017	$ 677.5	$ 1.4	$ 576.6	$ (97.4)	$ 256.7	$ (59.8)