CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net (loss) income	$ (29,892)us-gaap_NetIncomeLoss	$ (12,834)us-gaap_NetIncomeLoss	$ 29,978us-gaap_NetIncomeLoss
Other comprehensive (loss) income:
Amortization of prior service cost	154	167	177
Actuarial (gain) loss	1,013	(762)	681
Amortization of actuarial loss	(70)	(111)	(80)
Adjustments to net periodic postretirement (benefit) loss	1,097	(706)	778
Comprehensive (loss) income	$ (30,989)us-gaap_ComprehensiveIncomeNetOfTax	$ (12,128)us-gaap_ComprehensiveIncomeNetOfTax	$ 29,200us-gaap_ComprehensiveIncomeNetOfTax

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount of gain (loss) related to change in benefit obligation resulting from changes in actuarial assumptions, for example, but not limited to, interest, mortality, employee turnover, salary, and temporary deviation from the substantive plan.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount after tax of (increase) decrease in the value of the projected benefit obligation related to a change in an actuarial assumption and increase (decrease) in the value of the plan assets resulting from experience different from that assumed, that has not been recognized in net periodic benefit (cost) credit.

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Amount after tax of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) related to pension and other postretirement benefit plans.

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