Employee Benefit Plans - Funded Status of Pension Plan (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Amounts recognized in the Consolidated Balance Sheets
Noncurrent asset	$ 51,133	$ 58,708
Pension Plans
Amounts recognized in the Consolidated Balance Sheets
Noncurrent asset	51,133	58,708
Current liability	(3,754)	(3,863)
Noncurrent liability	(456,979)	(412,417)
Net amount recognized	(409,600)	(357,572)
Amounts recognized in accumulated other comprehensive loss (pre-tax)
Prior service cost	14,519	11,135
Net actuarial loss	929,995	878,386
Net amount recognized	$ 944,514	$ 889,521

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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