Goodwill and Intangible Assets Goodwill (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013
Changes in carrying amounts of goodwill
Beginning Goodwill Gross	$ 130,517
Accumulated impairment losses	(60,217)		(60,217)
Goodwill Net Beginning Balance	70,300
Currency valuation	(293)
Ending Goodwill Gross	130,224	130,517
Goodwill Net Ending Balance	70,007	70,300
Goodwill, Impairment Loss	0
Goodwill, Excess Fair Value over Carrying Value, Reporting Unit		less than 10%
Metals Segment
Changes in carrying amounts of goodwill
Beginning Goodwill Gross	117,544
Accumulated impairment losses	(60,217)		(60,217)
Goodwill Net Beginning Balance	57,327
Currency valuation	(293)
Ending Goodwill Gross	117,251
Goodwill Net Ending Balance	57,034
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

Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

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+ Details

- Definition

Loss recognized during the period that results from the write-down of goodwill after comparing the implied fair value of reporting unit goodwill with the carrying amount of that goodwill. Goodwill is assessed at least annually for impairment.

+ References

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+ Details