Accumulated Other Comprehensive Income (Loss) (Reclassification) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net		$ (1,788)	$ (8,492)	$ (1,194)
Income tax expense		(33,997)	(19,853)	(27,812)
Net income		48,283	46,320	$ 53,412
Unrealized gain (loss) on derivative instruments
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, net of tax	[1]	(11)	(84)
Accumulated defined benefit plans adjustment, Net gain (loss) attributable to parent
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes		246	1,486
Funded status of pension plans and other postretirement benefits
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from AOCI, tax		(86)	(520)
Reclassification from AOCI, net of tax	[2]	(160)	(966)
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		16
Realized gain (loss)			129
Income tax expense		(5)	(45)
Net income		$ 11	$ 84

[1] Net of taxes of $0 and $5 for the years ended December 31, 2016 and December 31, 2015, respectively.

[2] Net of taxes of $9,160 and $9,879 for the years ended December 31, 2016 and December 31, 2015, respectively.