Consolidated Statements of Changes in Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common stock	Additional Paid-in Capital	Accumulated Deficit	Treasury stock
Balances at Dec. 31, 2012	$ 30,962	$ 2	$ 356,895	$ (247,096)	$ (78,839)
Balances (in shares) at Dec. 31, 2012	3,030				3,030
Balances (in shares) at Dec. 31, 2012		26,481
Increase (Decrease) in Stockholders' Equity
Net income	11,395			11,395
Stock-based compensation to employees and directors	1,568		1,568
Common stock issued upon vesting of restricted stock (in shares)		334
Exercise of stock options	986		986
Exercise of stock options (in shares)		58
Purchase of treasury stock	(1,389)				(1,389)
Purchase of treasury stock (in shares)					94
Balances at Jun. 30, 2013	$ 43,522	$ 2	$ 359,449	$ (235,701)	$ (80,228)
Balances (in shares) at Jun. 30, 2013	3,124				3,124
Balances (in shares) at Jun. 30, 2013		26,873