Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Consolidated Statements of Comprehensive Income [Abstract]
Net Earnings	$ 46,614	$ 32,088	$ 50,651
Other Comprehensive Income (Loss):
Foreign currency translation adjustments	109	(12,520)	(10,112)
Pension and retiree medical benefits	(2,248)	4,121	(5,382)
Cash Flow Hedge	(305)	164	0
Income Taxes:
Foreign currency translation adjustments	32	25	13
Pension and retiree medical benefits	504	(1,265)	1,859
Cash Flow Hedge	114	(61)	0
Total Other Comprehensive Loss, net of tax	(1,794)	(9,536)	(13,622)
Comprehensive Income	$ 44,820	$ 22,552	$ 37,029