Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
NET EARNINGS	$ 2,163	$ 6,561	$ 21,956	$ 26,454
Other comprehensive income (loss), net of tax	0	0	0	(4)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(256)	(55)	54	(351)
OTHER COMPREHENSIVE INCOME (LOSS):
Income tax (expense) or benefit		0		46
TOTAL COMPREHENSIVE INCOME, net of tax	4,062	7,608	28,475	29,405
Pension Plans [Member]
Other comprehensive income (loss), net of tax	2,146	1,142	6,438	3,426
OTHER COMPREHENSIVE INCOME (LOSS):
Income tax (expense) or benefit	(1,222)	(651)	(3,666)	(1,953)
Post-Retirement Plans [Member]
Other comprehensive income (loss), net of tax	9	(40)	27	(120)
OTHER COMPREHENSIVE INCOME (LOSS):
Income tax (expense) or benefit	(5)	$ 23	(15)	69
Retained Earnings [Member]
OTHER COMPREHENSIVE INCOME (LOSS):
TOTAL COMPREHENSIVE INCOME, net of tax	$ 2,163		$ 21,956	$ 26,454