Accumulated Other Comprehensive Loss (Reclassification) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net	$ (592)	$ (994)	$ 5,019
Income tax (expense) benefit	(7,807)	(22,938)	(52,466)
Net income	47,319	87,651	$ 80,459
Amounts reclassified from accumulated other comprehensive income (loss) for the period ended December 31, 2013 | Funded status of pension plans and other postretirement benefits
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Pension settlement charges	(53,213)	0
Other income (expense), net	(504)	(227)
Income tax (expense) benefit	9,393	51
Net income	(44,324)	(176)
Amounts reclassified from accumulated other comprehensive income (loss) for the period ended December 31, 2013 | Unrealized gain (loss) on derivative instruments
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net	200	247
Income tax (expense) benefit	(45)	(56)
Net income	$ 155	$ 191