Goodwill and Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Goodwill, Gross
Balance, beginning of period			$ 221.7
Purchase accounting adjustments			11.5
Foreign currency fluctuations			(1.2)
Balance, end of period	$ 232.0		232.0		$ 221.7
Accumulated Impairment Losses
Balance, beginning of period			(39.0)
Foreign currency fluctuations			0.3
Balance, end of period	(38.7)		(38.7)		(39.0)
Goodwill, Net
Balance, beginning of period			182.7
Purchase accounting adjustments			11.5
Foreign currency fluctuations			(0.9)
Balance, end of period	193.3		193.3		182.7
Acquired Finite-lived Intangible Assets
Original cost	205.7		205.7		191.0
Accumulated amortization	(55.6)		(55.6)		(44.5)
Carrying value	150.1		150.1		146.5
Purchase of Intangible Assets			0.4	$ 1.2
Amortization expense	5.8	$ 5.8	11.5	$ 11.7
Estimated aggregate amortization expense of Intangible Assets
Remaining 2019	11.1		11.1
2020	20.8		20.8
2021	19.2		19.2
2022	17.1		17.1
2023	15.5		15.5
Thereafter	66.4		66.4
Total	150.1		150.1
Gaomei
Acquired Finite-lived Intangible Assets
Purchase of Intangible Assets			15.6
Customer Lists
Acquired Finite-lived Intangible Assets
Original cost	156.2		156.2		143.0
Accumulated amortization	(42.1)		(42.1)		(33.7)
Carrying value	114.1		$ 114.1		$ 109.3
Weighted-average original life (in years)			14 years		15 years
Trade Names
Acquired Finite-lived Intangible Assets
Original cost	32.2		$ 32.2		$ 30.6
Accumulated amortization	(6.8)		(6.8)		(5.3)
Carrying value	25.4		$ 25.4		$ 25.3
Weighted-average original life (in years)			11 years		10 years
Technology
Acquired Finite-lived Intangible Assets
Original cost	17.3		$ 17.3		$ 17.4
Accumulated amortization	(6.7)		(6.7)		(5.5)
Carrying value	$ 10.6		$ 10.6		$ 11.9
Weighted-average original life (in years)			11 years		10 years