CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY AND COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	Common Stock [Member]	Capital In Excess of Par Value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Treasury Stock [Member]	Total
BALANCE at Dec. 31, 2008	$ 40,972	$ 58,841	$ 76,600	$ 7,799	$ (20,667)	$ 163,545
Comprehensive Income:
Net income			3,483			3,483
Foreign currency translation adjustment				1,209		1,209
Pension and retiree medical adjustment, net of tax				(3,533)		(3,533)
Total comprehensive income						1,159
Issuance of common stock, net of offering costs	6,900	20,609				27,509
Stock-based compensation and related tax benefits		(615)			1,464	849
Stock options and related tax benefits		87			388	475
Employee Stock Ownership Plan		(1,684)			2,025	341
BALANCE at Dec. 31, 2009	47,872	77,238	80,083	5,475	(16,790)	193,878
Comprehensive Income:
Net income			21,960			21,960
Foreign currency translation adjustment				775		775
Pension and retiree medical adjustment, net of tax				(5,534)		(5,534)
Total comprehensive income						17,201
Stock-based compensation and related tax benefits		440			1,149	1,589
Stock options and related tax benefits		6			48	54
Employee Stock Ownership Plan		(249)			1,882	1,633
Cash dividends			(4,508)			(4,508)
Adjustment to costs related to issuance of common stock		36				36
BALANCE at Dec. 31, 2010	47,872	77,471	97,535	716	(13,711)	209,883
Comprehensive Income:
Net income			62,401			62,401
Foreign currency translation adjustment				(1,512)		(1,512)
Pension and retiree medical adjustment, net of tax				4,095		4,095
Total comprehensive income						64,984
Stock-based compensation and related tax benefits		1,136			1,056	2,192
Stock options and related tax benefits		634			2,263	2,897
Employee Stock Ownership Plan		548			1,966	2,514
Cash dividends			(6,381)			(6,381)
Purchase of treasury stock					(4,136)	(4,136)
BALANCE at Dec. 31, 2011	$ 47,872	$ 79,789	$ 153,555	$ 3,299	$ (12,562)	$ 271,953