Commitments and Contingent Liabilities (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended	12 Months Ended
	Sep. 30, 2011	Dec. 31, 2011	Dec. 31, 2012
Commitments and Contingencies Disclosure [Abstract]
Irrevocable letters of credit outstanding			$ 6,794
Collateral associated with commodity hedges			4,000
Compliance with the insurance reserve requirements of its workers' compensation insurance carriers			1,994
Total transaction value of exports		13
Civil Penalty Paid for Export Violations	775
Loss Contingency, Range of Possible Loss, Maximum			$ 1,250