Segment Information - By Reportable Segment (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) segment	Sep. 30, 2017 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment			2
Segment Reporting Information [Line Items]
Net sales	$ 235.8	$ 204.4	$ 679.2	$ 597.3
Operating income from continuing operations	18.4	12.5	47.8	34.5
Reportable Segments | IPG
Segment Reporting Information [Line Items]
Net sales	235.8	204.4	679.2	597.3
Operating income from continuing operations	23.9	19.8	63.2	55.2
Reportable Segments | NATG
Segment Reporting Information [Line Items]
Operating income from continuing operations	(0.8)	(0.3)	(0.8)	(0.7)
Corporate and Other
Segment Reporting Information [Line Items]
Operating income from continuing operations	$ (4.7)	$ (7.0)	$ (14.6)	$ (20.0)