Consolidated Condensed Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Preferred stock, par value (dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares outstanding	0	0
Common stock, par value (dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	31,299,194	31,299,194
Treasury stock, shares	3,455,985	2,925,801