CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock Issued	Additional Paid-in Capital	Accumulated Deficit	Treasury Stock	Accumulated Other Comprehensive Loss
Balance at Dec. 31, 2018			$ 1,578.1	$ (242.4)	$ (5.3)	$ (33.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise or redemption of share-based awards			2.7
Stock-based compensation expense			6.0
Net income (loss)	$ (28.3)			(28.3)
Purchases of treasury stock					(3.3)
Other comprehensive income (loss), net of tax						2.6
Balance at Jun. 30, 2019	1,276.9	$ 0.5	1,586.8	(270.7)	(8.6)	(31.1)
Balance at Mar. 31, 2019			1,582.5	(262.7)	(7.2)	(33.0)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise or redemption of share-based awards			2.5
Stock-based compensation expense			1.8
Net income (loss)	(8.0)			(8.0)
Purchases of treasury stock					(1.4)
Other comprehensive income (loss), net of tax						1.9
Balance at Jun. 30, 2019	1,276.9	0.5	1,586.8	(270.7)	(8.6)	(31.1)
Balance at Dec. 31, 2019	1,265.2		1,593.9	(288.3)	(8.9)	(32.0)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise or redemption of share-based awards			0.5
Stock-based compensation expense			5.5
Net income (loss)	0.7			0.7
Purchases of treasury stock					(0.3)
Other comprehensive income (loss), net of tax						(10.0)
Balance at Jun. 30, 2020	1,261.6	0.5	1,599.9	(287.6)	(9.2)	(42.0)
Balance at Mar. 31, 2020			1,596.4	(284.6)	(8.9)	(46.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise or redemption of share-based awards			0.5
Stock-based compensation expense			3.0
Net income (loss)	(3.0)			(3.0)
Purchases of treasury stock					(0.3)
Other comprehensive income (loss), net of tax						4.9
Balance at Jun. 30, 2020	$ 1,261.6	$ 0.5	$ 1,599.9	$ (287.6)	$ (9.2)	$ (42.0)