CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) [Abstract]
Net earnings	$ 19,244	$ 13,378	$ 31,448	$ 22,326
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(1,938)	822	(153)	(2,252)
Amortization of:
Prior service benefit	(14)	(29)	(27)	(58)
Unrecognized loss	115	512	390	1,130
Unrecognized actuarial gains	301	421	301	421
Foreign currency exchange rate changes	0	25	4	33
Income tax expense related to pension and postretirement plans	(164)	(367)	(272)	(608)
Pension and postretirement plans, net of tax	238	562	396	918
Total other comprehensive income (loss), net of tax	(1,700)	1,384	243	(1,334)
Comprehensive income	$ 17,544	$ 14,762	$ 31,691	$ 20,992