CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) (USD $) In Thousands, unless otherwise specified	Common Stock [Member]	Capital In Excess of Par Value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2012	$ 47,872	$ 82,348	$ 186,693	$ 3,879	$ (13,205)	$ 307,587
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	0	0	9,174	0	0	9,174
Other comprehensive income (loss), net of tax	0	0	0	(1,011)	0	(1,011)
Cash dividends paid	0	0	(2,510)	0	0	(2,510)
Purchase of treasury stock	0	0	0	0	(602)	(602)
Stock-based compensation and related tax benefits	0	543	0	0	8	551
Stock options exercised and related tax benefits	0	4	0	0	86	90
Employee Stock Ownership Plan	0	2,214	0	0	2,162	4,376
Balance at Mar. 31, 2013	$ 47,872	$ 85,109	$ 193,357	$ 2,868	$ (11,551)	$ 317,655