Comprehensive Income (Loss) (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accumulated other comprehensive income (loss), net of tax
Balance	$ (34,635)	$ 2,656
Total other comprehensive income (loss), net of tax	(2,180)	1,875
Balance	(19,184)	(34,635)
Defined Benefit Pension Items
Accumulated other comprehensive income (loss), net of tax
Balance	(45,418)	(46,977)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(1,166)	1,559
Total other comprehensive income (loss), net of tax	(1,166)	1,559
Balance	(46,584)	(45,418)
Foreign Currency Items
Accumulated other comprehensive income (loss), net of tax
Balance	1,115	799
Other comprehensive loss, net of tax, before reclassifications	(1,014)	316
Total other comprehensive income (loss), net of tax	(1,014)	316
Balance	101	1,115
Accumulated Other Comprehensive Income (Loss)
Accumulated other comprehensive income (loss), net of tax
Balance	(44,303)	(46,178)
Other comprehensive loss, net of tax, before reclassifications	(1,014)	316
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(1,166)	1,559
Total other comprehensive income (loss), net of tax	(2,180)	1,875
Balance	$ (46,483)	$ (44,303)