Consolidated Statements of Stockholders’ Equity - USD ($) $ in Millions	Total	Common Stock	Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Accumulated Deficit
Balance at start of period at Dec. 31, 2014	$ 681.0	$ 1.1	$ 2,031.5	$ (292.6)	$ (5.9)	$ (1,053.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	85.9	0.0	0.0	0.0	0.0	85.9
Income (loss) on derivative financial instrument, net of tax	(1.9)	0.0	0.0	(1.9)	0.0	0.0
Translation impact	(136.7)	0.0	0.0	(136.7)	0.0	0.0
Pension and post-retirement adjustment, net of tax	2.0	0.0	0.0	2.0	0.0	0.0
Common stock repurchases	(60.0)	(0.1)	(59.9)	0.0	0.0	0.0
Stock-based compensation	16.0	0.0	16.0	0.0	0.0	0.0
Common stock issued, net of shares withheld for employee taxes	(5.2)	0.0	0.7	0.0	(5.9)	0.0
Other	0.1	0.1	0.0	0.0	0.0	0.0
Balance at end of period at Dec. 31, 2015	$ 581.2	$ 1.1	1,988.3	(429.2)	$ (11.8)	(967.2)
Balance at start of period (in shares) at Dec. 31, 2014	111,911,290	112,670,514			759,224
Increase (Decrease) In Capital Stock [Roll Forward]
Common stock issued, net of shares withheld for employee taxes	1,419,341	2,149,165			729,824
Common stock repurchases	(7,690,628)	(7,690,628)			0
Balance at end of period (in shares) at Dec. 31, 2015	105,640,003	107,129,051			1,489,048
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 95.5	$ 0.0	0.0	0.0	$ 0.0	95.5
Income (loss) on derivative financial instrument, net of tax	1.7	0.0	0.0	1.7	0.0	0.0
Translation impact	16.8	0.0	0.0	16.8	0.0	0.0
Pension and post-retirement adjustment, net of tax	(8.7)	0.0	0.0	(8.7)	0.0	0.0
Stock-based compensation	19.4	0.0	19.4	0.0	0.0	0.0
Common stock issued, net of shares withheld for employee taxes	1.6	0.0	6.8	0.0	(5.2)	0.0
Adjustment due to the adoption of ASU 2016-09	1.2	0.0	1.2	0.0	0.0	0.0
Balance at end of period at Dec. 31, 2016	$ 708.7	$ 1.1	2,015.7	(419.4)	$ (17.0)	(871.7)
Increase (Decrease) In Capital Stock [Roll Forward]
Common stock issued, net of shares withheld for employee taxes	2,266,641	2,957,232			690,591
Common stock repurchases	0
Balance at end of period (in shares) at Dec. 31, 2016	107,906,644	110,086,283			2,179,639
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 131.7	$ 0.0	0.0	0.0	$ 0.0	131.7
Income (loss) on derivative financial instrument, net of tax	(2.3)	0.0	0.0	(2.3)	0.0	0.0
Translation impact	(19.5)	0.0	0.0	(19.5)	0.0	0.0
Pension and post-retirement adjustment, net of tax	(19.9)	0.0	0.0	(19.9)	0.0	0.0
Common stock repurchases	(36.6)	0.0	(36.6)	0.0	0.0	0.0
Stock-based compensation	17.0	0.0	17.0	0.0	0.0	0.0
Common stock issued, net of shares withheld for employee taxes	(5.2)	0.0	4.2	0.0	(9.4)	0.0
Adjustment due to the adoption of ASU 2016-09	0.2	0.0	(0.6)	0.0	0.0	0.8
Balance at end of period at Dec. 31, 2017	$ 774.1	$ 1.1	$ 1,999.7	$ (461.1)	$ (26.4)	$ (739.2)
Increase (Decrease) In Capital Stock [Roll Forward]
Common stock issued, net of shares withheld for employee taxes	2,045,321	2,778,795			733,474
Common stock repurchases	(3,267,881)	(3,267,881)			0
Balance at end of period (in shares) at Dec. 31, 2017	106,684,084	109,597,197			2,913,113