Long-term Debt Principal payments under the Energy Credit Agreement (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Debt Disclosure [Abstract]
2014	$ 13,214
2015	13,214
2016	13,214
2017	13,214
2018	39,644
Total	92,500
Less current portion	13,214	4,000
Total long-term debt	$ 79,286	$ 9,000

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