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, 2013	$ 47,872	$ 87,563	$ 228,036	$ 1,786	$ (15,825)	$ 349,432
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings	0	0	22,365	0	0	22,365
Other comprehensive income (loss), net of tax	0	0	0	(902)	0	(902)
Cash dividends paid	0	0	(5,955)	0	0	(5,955)
Purchase of treasury stock	0	0	0	0	(5,860)	(5,860)
Stock-based compensation and related tax benefits	0	1,992	0	0	516	2,508
Stock options exercised and related tax benefits	0	17	0	0	123	140
Employee Stock Ownership Plan	0	826	0	0	1,000	1,826
Balance at Jun. 30, 2014	$ 47,872	$ 90,398	$ 244,446	$ 884	$ (20,046)	$ 363,554