Other Comprehensive Income (Loss) Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021		Mar. 31, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances	$ 584,250		$ 697,480
Total other comprehensive income (loss)	630		(3,680)
Balances	595,970		675,460
Other Comprehensive Income (Loss), Tax [Abstract]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	(1,300)		1,500
Defined Benefit Plans [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances	(8,620)		(9,930)
Net unrealized gains (losses) arising during the period	0		0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(150)		(150)
Total other comprehensive income (loss)	150		150
Balances	(8,470)		(9,780)
Accumulated Net Gain (Loss) from Hedges Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances	(3,580)		4,230
Net unrealized gains (losses) arising during the period	3,900	[1]	4,430	[2]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0		0
Total other comprehensive income (loss)	3,900		4,430
Balances	320		8,660
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances	6,580		(300)
Net unrealized gains (losses) arising during the period	(3,420)		(8,260)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0		0
Total other comprehensive income (loss)	(3,420)		(8,260)
Balances	3,160		(8,560)
Accumulated Other Comprehensive Income [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balances	(5,620)		(6,000)
Net unrealized gains (losses) arising during the period	480		(3,830)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(150)		(150)
Total other comprehensive income (loss)	630		(3,680)
Balances	$ (4,990)		$ (9,680)

[1] Derivative instruments, net of income tax of approximately $1.3 million. See Note 11, "Derivative Instruments," for further details

[2] Derivative instruments, net of income tax of approximately $1.5 million. See Note 11, "Derivative Instruments," for further details.