Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock	Capital in Excess of Par	Accumulated Other Comprehensive Income (Loss)	Retained Earnings
Balance at Dec. 31, 2009	$ 155,472	$ 10,953	$ 12,086	$ (1,664)	$ 134,097
Balance, shares at Dec. 31, 2009		8,762,383
Cumulative adjustment due to consolidation of equity investee, net of taxes	(602)				(602)
Net income	9,746				9,746
Other comprehensive loss	(612)			(612)
Stock-based compensation	1,342		1,342
Issuance of common stock under awards, rights and options and related tax benefit	(120)	35	(155)
Issuance of common stock under awards, rights and options and related tax benefit share		28,016
Balance at Dec. 31, 2010	165,226	10,988	13,273	(2,276)	143,241
Balance, shares at Dec. 31, 2010		8,790,399
Net income	36,435				36,435
Other comprehensive loss	(1,074)			(1,074)
Stock-based compensation	1,580		1,580
Issuance of common stock under awards, rights and options and related tax benefit	(122)	52	(174)
Issuance of common stock under awards, rights and options and related tax benefit share		41,778
Balance at Dec. 31, 2011	202,045	11,040	14,679	(3,350)	179,676
Balance, shares at Dec. 31, 2011		8,832,177
Net income	13,194				13,194
Cash dividends declared	(90,439)				(90,439)
Repurchase of common stock	(2,510)	(126)	(2,384)
Repurchase of common stock, shares	0	(100,852)
Other comprehensive loss	(1,368)			(1,368)
Stock-based compensation	2,458		2,458
Issuance of common stock under awards, rights and options and related tax benefit	(245)	64	(309)
Issuance of common stock under awards, rights and options and related tax benefit share		50,849
Balance at Dec. 31, 2012	$ 123,135	$ 10,978	$ 14,444	$ (4,718)	$ 102,431
Balance, shares at Dec. 31, 2012		8,782,174