CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) [Abstract]
Net earnings	$ 13,378	$ 10,640	$ 22,326	$ 22,365
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	822	(141)	(2,252)	(731)
Amortization of:
Prior service benefit	(29)	(755)	(58)	(1,509)
Unrecognized loss	512	546	1,130	1,138
Unrecognized actuarial gains	421	150	421	150
Foreign currency exchange rate changes	25	(3)	33	(25)
Income tax (expense) benefit related to pension and postretirement plans	(367)	17	(608)	75
Pension and postretirement plans, net of tax	562	(45)	918	(171)
Total other comprehensive income (loss), net of tax	1,384	(186)	(1,334)	(902)
Comprehensive income	$ 14,762	$ 10,454	$ 20,992	$ 21,463