Consolidated Statement of Stockholders' Equity (USD $) In Thousands, except Share data	Total	Common Stock	Repurchased Stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)
Beginning Balance at Dec. 31, 2009	$ 82,018	$ 183		$ 136,380	$ (54,545)
Beginning Balance (in shares) at Dec. 31, 2009		18,275,655
Stock issued for cash (in shares)		322,134
Stock issued for cash	1,121	3		1,118
Stock issued for director compensation (in shares)		4,424
Stock issued for director compensation	174			174
Repurchased shares of common and restricted stock from stockholders (in shares)		(9,625)	(682,046)
Repurchased shares of common and restricted stock from stockholders	(20,240)		(19,966)	(274)
Stock-based compensation	2,805			2,805
Excess tax benefit from stock based compensation	1,554			1,554
Net income	29,868				29,868
Ending Balance at Dec. 31, 2010	97,300	186	(19,966)	141,757	(24,677)
Ending Balance (in shares) at Dec. 31, 2010		18,592,588	(682,046)
Stock issued for cash (in shares)		155,472
Stock issued for cash	910	1		909
Stock issued for director compensation (in shares)		3,540
Stock issued for director compensation	139			139
Repurchased shares of common and restricted stock from stockholders (in shares)	(219,208)	(6,050)	(219,208)
Repurchased shares of common and restricted stock from stockholders	(9,745)		(9,521)	(224)
Stock-based compensation	3,189			3,189
Repurchased and retired shares of common stock (in shares)		(901,254)	901,254
Repurchased and retired shares of common stock		(9)	29,487		(29,478)
Excess tax benefit from stock based compensation	1,283			1,283
Net income	40,757				40,757
Ending Balance at Dec. 31, 2011	133,833	178		147,053	(13,398)
Ending Balance (in shares) at Dec. 31, 2011		17,844,296
Stock issued for cash (in shares)		408,739
Stock issued for cash	4,058	5		4,053
Stock issued for director compensation (in shares)		3,098
Stock issued for director compensation	116			116
Repurchased shares of common and restricted stock from stockholders (in shares)	(493,491)	(10,697)	(493,491)
Repurchased shares of common and restricted stock from stockholders	(15,856)		(15,399)	(457)
Stock-based compensation	3,818			3,818
Repurchased and retired shares of common stock (in shares)		(493,491)	493,491
Repurchased and retired shares of common stock	(5)	(5)	15,399		(15,399)
Excess tax benefit from stock based compensation	2,866			2,866
Net income	42,323				42,323
Ending Balance at Dec. 31, 2012	$ 171,153	$ 178		$ 157,449	$ 13,526
Ending Balance (in shares) at Dec. 31, 2012		17,751,945