Segment Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017 USD ($) segment	Mar. 31, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment	2
Number of reportable segments | segment	2
Net Sales [Abstract]
Net sales	$ 233.3	$ 214.6
Percentage of Net Sales (in hundredths)	100.00%	100.00%
Operating Profit [Abstract]
Operating Profit	$ 26.6	$ 31.6
Operating Profit (in hundredths)	100.00%	100.00%
Operating Segments [Member] | Engineered Papers [Member]
Net Sales [Abstract]
Net sales	$ 133.3	$ 143.6
Percentage of Net Sales (in hundredths)	57.10%	66.90%
Operating Profit [Abstract]
Operating Profit	$ 26.9	$ 35.5
Operating Profit (in hundredths)	101.10%	112.30%
Operating Segments [Member] | Advanced Materials & Structures [Member]
Net Sales [Abstract]
Net sales	$ 100.0	$ 71.0
Percentage of Net Sales (in hundredths)	42.90%	33.10%
Operating Profit [Abstract]
Operating Profit	$ 8.9	$ 5.2
Operating Profit (in hundredths)	33.50%	16.50%
Unallocated [Member]
Operating Profit [Abstract]
Operating Profit	$ (9.2)	$ (9.1)
Operating Profit (in hundredths)	(34.60%)	(28.80%)