Goodwill and Other Intangible Assets - Changes in carrying value of goodwill (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Goodwill impairment		$ 0	$ 0	$ 0
Goodwill [Roll Forward]
Goodwill, net, beginning balance	$ 72,200,000	70,400,000	72,200,000
Adjustment of goodwill acquired in the Fibermark Acquisition			(400,000)
Foreign currency translation		4,900,000	(1,400,000)
Goodwill acquired in the Coldenhove Acquisition		10,000,000
Goodwill, net, ending balance		$ 85,300,000	70,400,000	72,200,000
Minimum
Goodwill [Line Items]
Useful lives		10 years
Maximum
Goodwill [Line Items]
Useful lives		15 years
Technical Products
Goodwill [Roll Forward]
Goodwill gross, beginning balance	110,700,000	$ 107,400,000	110,700,000
Accumulated Impairment Loss, beginning of period	(45,100,000)	(43,600,000)	(45,100,000)
Goodwill, net, beginning balance	65,600,000	63,800,000	65,600,000
Adjustment of goodwill acquired in the Fibermark Acquisition	(400,000)		(400,000)
Foreign currency translation gross impact		10,900,000	(2,900,000)
Foreign currency translation, Accumulated Impairment Losses Impact		(6,000,000)	1,500,000
Foreign currency translation		4,900,000	(1,400,000)
Goodwill acquired in the Coldenhove Acquisition		10,000,000
Goodwill gross, ending balance		128,300,000	107,400,000	110,700,000
Accumulated Impairment Loss, end of period		(49,600,000)	(43,600,000)	(45,100,000)
Goodwill, net, ending balance		78,700,000	63,800,000	65,600,000
Fine Paper and Packaging
Goodwill [Roll Forward]
Goodwill gross, beginning balance	6,200,000	6,200,000	6,200,000
Goodwill gross, ending balance		6,200,000	6,200,000	6,200,000
Other
Goodwill [Roll Forward]
Goodwill gross, beginning balance	$ 400,000	400,000	400,000
Goodwill gross, ending balance		400,000	$ 400,000	$ 400,000
W.A. Sanders Coldenhove Holding B.V.
Goodwill [Roll Forward]
Goodwill, net, ending balance		10,000,000
W.A. Sanders Coldenhove Holding B.V. | Technical Products
Goodwill [Roll Forward]
Goodwill acquired in the Coldenhove Acquisition		$ 10,000,000