Accumulated Other Comprehensive Loss (Reclassifications out of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net of tax	$ (1,486)	$ (1,712)
Amortization of actuarial losses
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification	(1,555)	(2,195)
Prior service costs
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification	(138)	(81)
Pension and other post-retirement effects
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Tax benefit	207	564
Net of tax	$ (1,486)	$ (1,712)

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Amount before tax of reclassification adjustments of other comprehensive income (loss).

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