Business Segments (Reconciliation of Operating Profit (Loss) from Segments to Consolidated) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Business Segments [Abstract]
Income for reportable segments	$ 11,929	$ 12,933	$ 21,187	$ 20,051
Interest expense	(1,288)	(126)	(1,901)	(249)
Interest income	37	147	94	291
Other income	(95)	138	708	273
LIFO income (expense)	406	202	400	198
Equity in (loss) income of nonconsolidated investment	(186)	142	(13)	346
Corporate expense, cost of capital elimination and other unallocated charges	(2,980)	(3,206)	(5,985)	(5,359)
Income before income taxes	$ 7,823	$ 10,230	$ 14,490	$ 15,551