Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	$ 5.0	$ 3.1
Estimated Amortization Expense
Estimated average amortization expense in each of next five years	20.2
Advanced Materials & Structures [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	337.3		$ 220.1
Accumulated Amortization	26.1		31.1
Accumulated Impairments	20.7		20.7
Accumulated Foreign Exchange	3.5		3.8
Net Carrying Amount	287.0		164.5
Advanced Materials & Structures [Member] | Trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Impairments	0.0		0.0
Accumulated Foreign Exchange	(0.1)		(0.1)
Indefinite-Lived Intangible Assets (Excluding Goodwill), Gross	20.0		12.9
Indefinite-Lived Intangible Assets (Excluding Goodwill)	20.1		13.0
Advanced Materials & Structures [Member] | Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	276.2		168.3
Accumulated Amortization	19.8		15.9
Accumulated Impairments	0.0		0.0
Accumulated Foreign Exchange	2.9		3.1
Net Carrying Amount	253.5		149.3
Advanced Materials & Structures [Member] | Developed technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	34.0		15.9
Accumulated Amortization	4.2		3.6
Accumulated Impairments	0.0		0.0
Accumulated Foreign Exchange	0.3		0.4
Net Carrying Amount	29.5		11.9
Advanced Materials & Structures [Member] | Customer contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	0.9		0.9
Accumulated Amortization	0.9		0.9
Accumulated Impairments	0.0		0.0
Accumulated Foreign Exchange	0.0		0.0
Net Carrying Amount	0.0		0.0
Advanced Materials & Structures [Member] | Trade names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	21.8		21.8
Accumulated Amortization	0.4		0.0
Accumulated Impairments	20.7		20.7
Accumulated Foreign Exchange	0.3		0.3
Net Carrying Amount	0.4		0.8
Advanced Materials & Structures [Member] | Non-compete agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2.9		1.7
Accumulated Amortization	0.6		0.5
Accumulated Impairments	0.0		0.0
Accumulated Foreign Exchange	0.0		0.0
Net Carrying Amount	2.3		1.2
Advanced Materials & Structures [Member] | Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1.5		1.5
Accumulated Amortization	0.2		0.2
Accumulated Impairments	0.0		0.0
Accumulated Foreign Exchange	0.0		0.0
Net Carrying Amount	1.3		1.3
Engineered Papers [Member] | Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount			10.0
Accumulated Amortization			10.0
Accumulated Impairments			0.0
Accumulated Foreign Exchange			$ 0.0
Conwed Plastics LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	$ 1.7