Accumulated Other Comprehensive Loss (Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		$ (88,458)	$ (65,094)
Other comprehensive income (loss) before reclassifications		10,930	(27,856)
Amounts reclassified from accumulated other comprehensive loss (4)		37	362
Other comprehensive income (loss)		10,967	(27,494)
Ending balance		(77,491)	(92,588)
AOCI, Pension and other postretirement benefit plans, tax		9,860	11,807	$ 9,879	$ 11,952
AOCI, Cumulative changes in net gain (loss) from cash flow hedges, tax		3	50	$ 5	$ 50
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(41,365)	(14,193)
Other comprehensive income (loss) before reclassifications		10,926	(27,980)
Amounts reclassified from accumulated other comprehensive loss (4)		0	0
Other comprehensive income (loss)		10,926	(27,980)
Ending balance		(30,439)	(42,173)
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 (loss) before reclassifications	[1]	0	0
Amounts reclassified from accumulated other comprehensive loss (4)	[1]	35	268
Other comprehensive income (loss)	[1]	35	268
Ending balance	[1]	(47,047)	(50,540)
Reclassification from AOCI, Current Period, Tax		19	144
Unrealized gain (loss) on derivative instruments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	[2]	(11)	(93)
Other comprehensive income (loss) before reclassifications	[2]	4	124
Amounts reclassified from accumulated other comprehensive loss (4)	[2]	2	94
Other comprehensive income (loss)	[2]	6	218
Ending balance	[2]	(5)	125
Reclassification from AOCI, Current Period, Tax		$ 1	$ 51

[1] Net of taxes of $11,807 and $11,952 as of March 31, 2015 and December 31, 2014, respectively. Net of taxes of $9,860 and $9,879 as of March 31, 2016, December 31, 2015, respectively.

[2] Net of taxes of $3 and $5 as of March 31, 2016 and December 31, 2015, respectively. Net of taxes of $50 and $50 as of March 31, 2015 and December 31, 2014, respectively.