Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2011	Dec. 31, 2010
Stockholder's equity:
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized shares	49,000,000	49,000,000
Common stock, issued shares	23,211,846	23,211,846
Common stock, outstanding shares	22,115,523	22,122,678
Treasury Stock Shares	1,096,323	1,089,168