CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
CONSOLIDATED BALANCE SHEETS
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	19,096,300	19,096,300
Common stock, shares outstanding	17,759,446	17,468,269
Treasury stock, shares	1,336,854	1,628,031