Segment Information - By Reportable Segment (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) segment	Mar. 31, 2017 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	2
Segment Reporting Information [Line Items]
Net sales	$ 355.2	$ 302.5
Operating income (loss)	20.1	12.4
Reportable Segments | IPG
Segment Reporting Information [Line Items]
Net sales	212.2	190.2
Operating income (loss)	16.3	12.5
Reportable Segments | ETG
Segment Reporting Information [Line Items]
Net sales	143.0	112.3
Operating income (loss)	9.3	5.8
Corporate and Other
Segment Reporting Information [Line Items]
Operating income (loss)	$ (5.5)	$ (5.9)