Goodwill and Intangible Assets - Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Intangible assets
Gross Carrying Amount, intangible assets subject to amortization	$ 257.5		$ 257.5		$ 236.0
Accumulated Amortization, intangible assets subject to amortization	(170.1)		(170.1)		(154.2)
Net Carrying Amount, intangible assets subject to amortization	87.4		87.4		81.8
Gross Carrying Amount, total intangible assets	258.1		258.1		236.6
Net Carrying Amount, total intangible assets	88.0		88.0		82.4
Amortization expense related to intangible assets subject to amortization	7.8	$ 7.5	14.6	$ 14.4
In-process research and development
Intangible assets
Gross Carrying Amount, intangible assets not subject to amortization	0.6		0.6		0.6
Net Carrying Amount, intangible assets not subject to amortization	0.6		0.6		0.6
Existing technology and related patents
Intangible assets
Gross Carrying Amount, intangible assets subject to amortization	206.8		206.8		195.4
Accumulated Amortization, intangible assets subject to amortization	(151.6)		(151.6)		(138.9)
Net Carrying Amount, intangible assets subject to amortization	55.2		55.2		56.5
Customer relationships
Intangible assets
Gross Carrying Amount, intangible assets subject to amortization	42.3		42.3		34.6
Accumulated Amortization, intangible assets subject to amortization	(15.0)		(15.0)		(12.9)
Net Carrying Amount, intangible assets subject to amortization	27.3		27.3		21.7
Non compete contracts
Intangible assets
Gross Carrying Amount, intangible assets subject to amortization	1.8		1.8		1.8
Accumulated Amortization, intangible assets subject to amortization	(1.7)		(1.7)		(1.5)
Net Carrying Amount, intangible assets subject to amortization	0.1		0.1		0.3
Trade names
Intangible assets
Gross Carrying Amount, intangible assets subject to amortization	4.8		4.8		4.2
Accumulated Amortization, intangible assets subject to amortization	(1.3)		(1.3)		(0.9)
Net Carrying Amount, intangible assets subject to amortization	3.5		3.5		$ 3.3
Other
Intangible assets
Gross Carrying Amount, intangible assets subject to amortization	1.8		1.8
Accumulated Amortization, intangible assets subject to amortization	(0.5)		(0.5)
Net Carrying Amount, intangible assets subject to amortization	$ 1.3		$ 1.3