CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME [Abstract]
Net earnings	$ 46,018	$ 43,029	$ 51,450
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(5,739)	(3,781)	(1,101)
Amortization of:
Prior service benefit	(112)	(3,017)	(4,317)
Unrecognized loss	2,261	2,435	3,123
Actuarial gains (losses)	462	(413)	(343)
Plan settlement	654	0	0
Foreign currency exchange rate changes	(23)	(34)	(32)
Income tax (expense) benefit related to pension and postretirement plans	(1,325)	372	577
Pension and post retirement plans, net of tax	1,917	(657)	(992)
Total other comprehensive income (loss), net of tax	(3,822)	(4,438)	(2,093)
Comprehensive income	$ 42,196	$ 38,591	$ 49,357