CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) [Abstract]
Net earnings	$ 10,640	$ 16,043	$ 22,365	$ 25,217
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(141)	(940)	(731)	(1,752)
Amortization of:
Prior service benefit	(755)	(1,080)	(1,509)	(2,160)
Unrecognized loss	546	776	1,138	1,561
Unrecognized amounts	150	154	150	154
Foreign currency exchange rate changes	(3)	(15)	(25)	(27)
Income tax benefit related to pension and postretirement plans	17	51	75	159
Pension and postretirement plans, net of tax	(45)	(114)	(171)	(313)
Total other comprehensive income (loss), net of tax	(186)	(1,054)	(902)	(2,065)
Comprehensive income	$ 10,454	$ 14,989	$ 21,463	$ 23,152