Business Segments (Reconciliation of Operating Profit (Loss) from Segments to Consolidated) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Business Segments [Abstract]
Income for reportable segments	$ 16,445	$ 13,553	$ 36,496	$ 35,261
Interest expense	(126)	(118)	(375)	(376)
Interest income	140	149	431	494
Other income	47	638	297	953
LIFO income (expense)	302	553	500	299
Equity in income of nonconsolidated investment	477	296	823	892
Corporate expense, cost of capital elimination and other unallocated charges	(3,423)	(1,049)	(8,782)	(4,962)
Income from continuing operations before income taxes	$ 13,862	$ 14,022	$ 29,390	$ 32,561