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Goodwill Impairment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Goodwill Impairment (Details) - USD ($) $ in Millions	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Goodwill [Line Items]
Goodwill	$ 531.9		$ 531.9		$ 641.9
Impairment of goodwill	114.4	$ 0.0	114.4	$ 0.0
Accumulated goodwill impairment loss	$ 241.0		241.0		$ 126.6
High Performance Materials & Components
Goodwill [Line Items]
Decrease in goodwill			(110.0)
Impairment of goodwill			114.4
Foreign currency translation impact on goodwill			$ (4.4)
Reporting Unit One \| High Performance Materials & Components
Goodwill [Line Items]
Percentage of fair value in excess of carrying value					12.00%