Goodwill and Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Goodwill, Gross
Balance, beginning of period			$ 221.7
Purchase accounting adjustments			11.1
Foreign currency fluctuations			(10.0)
Balance, end of period	$ 222.8		222.8		$ 221.7
Accumulated Impairment Losses
Balance, beginning of period			(39.0)
Foreign currency fluctuations			1.6
Balance, end of period	(37.4)		(37.4)		(39.0)
Goodwill, Net
Balance, beginning of period			182.7
Purchase accounting adjustments			11.1
Foreign currency fluctuations			(8.4)
Balance, end of period	185.4		185.4		182.7
Acquired Finite-lived Intangible Assets
Original cost	197.9		197.9		191.0
Accumulated amortization	(58.4)		(58.4)		(44.5)
Carrying value	139.5		139.5		146.5
Purchase of Intangible Assets			0.5	$ 2.6
Amortization expense	5.1	$ 5.7	16.6	$ 17.4
Estimated aggregate amortization expense of Intangible Assets
Remaining 2019	5.4		5.4
2020	19.9		19.9
2021	18.4		18.4
2022	16.3		16.3
2023	14.9		14.9
Thereafter	64.6		64.6
Total	139.5		139.5
Gaomei
Acquired Finite-lived Intangible Assets
Purchase of Intangible Assets			15.7
Customer Lists
Acquired Finite-lived Intangible Assets
Original cost	149.9		149.9		143.0
Accumulated amortization	(44.3)		(44.3)		(33.7)
Carrying value	105.6		$ 105.6		$ 109.3
Weighted-average original life (in years)			15 years		15 years
Trade Names
Acquired Finite-lived Intangible Assets
Original cost	31.0		$ 31.0		$ 30.6
Accumulated amortization	(7.3)		(7.3)		(5.3)
Carrying value	23.7		$ 23.7		$ 25.3
Weighted-average original life (in years)			11 years		10 years
Technology
Acquired Finite-lived Intangible Assets
Original cost	17.0		$ 17.0		$ 17.4
Accumulated amortization	(6.8)		(6.8)		(5.5)
Carrying value	$ 10.2		$ 10.2		$ 11.9
Weighted-average original life (in years)			11 years		10 years