Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 47,566	$ 50,972	$ 63,279	$ 82,227	$ 93,494	$ 105,060	$ 63,279	$ 105,060
Net change related to derivatives	(26)			60			(813)	1,253
Net current-period other comprehensive income (loss)	(1,660)	(741)	(1,294)	(8,170)	(9,217)	3,525
Balance	42,055	47,566	50,972	69,234	82,227	93,494	42,055	69,234
Foreign Currency Items [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(697)				(697)
Net current-period other comprehensive income (loss)							(3,033)
Balance	(3,730)						(3,730)
Unrealized Gain (Losses) On Available-For-Sale Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(18)				(18)
Net current-period other comprehensive income (loss)							1
Balance	(17)						(17)
Accrued Pension Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(1,822)				(1,822)
Net current-period other comprehensive income (loss)							155
Balance	(1,667)						(1,667)
Hedge Accounting Reserve [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			580				580
Total change in hedge fair value recorded in Other Comprehensive Income							(2)
Amounts reclassified from accumulated other comprehensive income							(811)
Net change related to derivatives							(813)
Net current-period other comprehensive income (loss)							(813)
Balance	(233)						(233)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(3,990)	(3,250)	(1,957)	(812)	8,406	4,882	(1,957)	4,882
Total change in hedge fair value recorded in Other Comprehensive Income							(2)
Amounts reclassified from accumulated other comprehensive income							(811)
Net change related to derivatives							(813)
Net current-period other comprehensive income (loss)	(1,657)	(740)	(1,293)	(8,167)	(9,218)	3,524	(3,690)
Balance	$ (5,647)	$ (3,990)	$ (3,250)	$ (8,979)	$ (812)	$ 8,406	$ (5,647)	$ (8,979)