Goodwill and Intangible Assets Goodwill (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
Changes in carrying amounts of goodwill
Beginning Goodwill Gross	$ 129,506
Accumulated impairment losses	(60,217)	(60,217)
Goodwill Net Beginning Balance	69,289
Currency valuation	(535)
Ending Goodwill Gross	128,971
Goodwill Net Ending Balance	68,754
Goodwill, Impairment Loss	0
Metals Segment
Changes in carrying amounts of goodwill
Beginning Goodwill Gross	116,533
Accumulated impairment losses	(60,217)	(60,217)
Goodwill Net Beginning Balance	56,316
Currency valuation	(535)
Ending Goodwill Gross	115,998
Goodwill Net Ending Balance	55,781
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount			13.00%
Plastics Segment
Changes in carrying amounts of goodwill
Beginning Goodwill Gross	12,973
Accumulated impairment losses	0	0
Goodwill Net Beginning Balance	12,973
Currency valuation	0
Ending Goodwill Gross	12,973
Goodwill Net Ending Balance	$ 12,973
Reporting Unit, Percentage of Fair Value in Excess of Carrying Amount			23.00%