Goodwill and Intangible Assets Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Changes in carrying amounts of goodwill
Beginning Goodwill	$ 129,350	$ 129,506
Accumulated impairment losses	(116,377)	(60,217)
Balance	12,973	69,289
Currency valuation	0	(156)
Ending Goodwill	129,350	129,350	$ 129,506
Accumulated impairment losses	(116,377)	(116,377)	(60,217)
Balance	12,973	12,973	69,289
Impairment of goodwill	0	56,160	0
Metals Segment
Changes in carrying amounts of goodwill
Beginning Goodwill	116,377	116,533
Accumulated impairment losses	(116,377)	(60,217)
Balance	0	56,316
Currency valuation	0	(156)
Ending Goodwill	116,377	116,377	116,533
Accumulated impairment losses	(116,377)	(116,377)	(60,217)
Balance	0	0	56,316
Impairment of goodwill	0	56,160
Deductible goodwill impairment loss		(13,900)
Plastics Segment
Changes in carrying amounts of goodwill
Beginning Goodwill	12,973	12,973
Accumulated impairment losses	0	0
Balance	12,973	12,973
Currency valuation	0	0
Ending Goodwill	12,973	12,973	12,973
Accumulated impairment losses	0	0	0
Balance	12,973	12,973	$ 12,973
Impairment of goodwill	$ 0	$ 0