Employee Benefits Plans (Details 3) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Amounts recognized in the Consolidated Balance Sheets
Noncurrent asset	$ 58,708	$ 14,049
Pension Plans
Amounts recognized in the Consolidated Balance Sheets
Noncurrent asset	58,708	14,049
Current liability	(3,863)	(3,796)
Noncurrent liability	(412,417)	(451,940)
Net amount recognized	(357,572)	(441,687)
Amounts recognized in accumulated other comprehensive loss (pre-tax)
Prior service cost	11,135	11,714
Net actuarial loss	878,386	961,010
Net amount recognized	$ 889,521	$ 972,724

Amount, before tax, of accumulated other comprehensive (income) loss for defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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