Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning balance at Dec. 31, 2018	$ 1,615.5	$ 1.4	$ 2,325.6	$ (335.6)	$ (375.9)
Balance, shares at Dec. 31, 2018		139,453,710
Cumulative-effect adjustment to accumulated deficit related to the adoption of ASU 2018-02 | ASU 2018-02 [Member]				27.1	(27.1)
Net income	11.2			11.2
Issuance of common stock under share-based compensation plans	20.1		20.1
Issuance of common stock under share-based compensation plans, shares		1,221,622
Share-based compensation	6.0		6.0
Foreign currency translation	12.3				12.3
Change in unrealized gain, net of tax	19.2				19.2
Change in pension liability adjustment, net of tax	2.5				2.5
Ending balance at Mar. 31, 2019	1,686.8	$ 1.4	2,351.7	(297.3)	(369.0)
Balance, shares at Mar. 31, 2019		140,675,332
Beginning balance at Dec. 31, 2019	1,882.3	$ 1.4	2,449.1	(229.8)	(338.4)
Balance, shares at Dec. 31, 2019		144,386,618
Net income	8.6			8.6
Issuance of common stock under share-based compensation plans	11.4		11.4
Issuance of common stock under share-based compensation plans, shares		551,328
Share-based compensation	12.5		12.5
Foreign currency translation	(49.1)				(49.1)
Change in unrealized gain, net of tax	17.4				17.4
Change in pension liability adjustment, net of tax	2.5				2.5
Ending balance at Mar. 31, 2020	$ 1,885.6	$ 1.4	$ 2,473.0	$ (221.2)	$ (367.6)
Balance, shares at Mar. 31, 2020		144,937,946