Accumulated Other Comprehensive Income (Loss) (Components of Accumulated Other Comprehensive Income or Loss) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance		$ 584,582	$ 587,281	$ 560,316
Actuarial net gain (loss) incurred in fiscal year		1,106	2,760	(20,715)
Ending Balance		635,786	584,582	587,281
AOCI, Pension and other postretirement benefit plans, tax		9,160	9,879	11,952
AOCI, Cumulative changes in net gain (loss) from cash flow hedges, tax		0	5	50
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance		(41,365)	(14,193)
Other comprehensive income before reclassifications		(5,081)	(27,172)
Actuarial net gain (loss) incurred in fiscal year		0	0
Amounts reclassified from accumulated other comprehensive income		0	0
Net current-period other comprehensive income		(5,081)	(27,172)
Ending Balance		(46,446)	(41,365)	(14,193)
Funded status of pension plans and other postretirement benefits
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	[1]	(47,082)	(50,808)
Other comprehensive income before reclassifications	[1]	0	0
Actuarial net gain (loss) incurred in fiscal year	[1]	1,106	2,760
Amounts reclassified from accumulated other comprehensive income	[1]	160	966
Net current-period other comprehensive income	[1]	1,266	3,726
Ending Balance	[1]	(45,816)	(47,082)	(50,808)
Unrealized gain (loss) on derivative instruments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance	[2]	(11)	(93)
Other comprehensive income before reclassifications	[2]	0	(2)
Actuarial net gain (loss) incurred in fiscal year	[2]	0	0
Amounts reclassified from accumulated other comprehensive income	[2]	11	84
Net current-period other comprehensive income	[2]	11	82
Ending Balance	[2]	0	(11)	(93)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning Balance		(88,458)	(65,094)	(11,450)
Other comprehensive income before reclassifications		(5,081)	(27,174)
Actuarial net gain (loss) incurred in fiscal year		1,106	2,760
Amounts reclassified from accumulated other comprehensive income		171	1,050
Net current-period other comprehensive income		(3,804)	(23,364)
Ending Balance		$ (92,262)	$ (88,458)	$ (65,094)

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

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