Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss
Balance (in shares) at Dec. 31, 2018		55,625,149
Balance at Dec. 31, 2018	$ 414.7	$ 0.0	$ 809.9	$ (368.3)	$ (26.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation for options issued	0.2		0.2
Share-based compensation for restricted stock issued (in shares)		562,385
Share-based compensation for restricted stock issued	8.5		8.5
Tax withholding related to the vesting of restricted stock (in shares)		(9,307)
Tax withholding related to the vesting of restricted stock	(0.3)		(0.3)
Stock issued in connection with employee stock purchase plan (in shares)		14,061
Stock issued in connection with employee stock purchase plan	0.1		0.1
Stock issued in connection with acquisitions (in shares)		(6,954)
Stock issued in connection with acquisitions	(0.3)		(0.3)
Stock options exercised (in shares)		41,704
Stock options exercised	0.4		0.4
Net loss	(27.3)			(27.3)
Foreign currency translation	(35.9)				(35.9)
Balance (in shares) at Mar. 31, 2019		56,227,038
Balance at Mar. 31, 2019	360.1	$ 0.0	818.5	(395.6)	(62.8)
Balance (in shares) at Dec. 31, 2019		56,686,459
Balance at Dec. 31, 2019	291.1	$ 0.0	842.4	(474.2)	(77.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation for restricted stock issued (in shares)		1,764,788
Share-based compensation for restricted stock issued	8.2		8.2
Tax withholding related to the vesting of restricted stock (in shares)		(23,783)
Tax withholding related to the vesting of restricted stock	(0.3)		(0.3)
Stock issued in connection with employee stock purchase plan (in shares)		23,619
Stock issued in connection with employee stock purchase plan	0.1		0.1
Net loss	(83.3)			(83.3)
Foreign currency translation	(9.9)				(9.9)
Balance (in shares) at Mar. 31, 2020		58,451,083
Balance at Mar. 31, 2020	$ 196.8	$ 0.0	$ 850.4	$ (566.6)	$ (87.0)