Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	60,000,000	60,000,000
Common stock, shares issued	20,556,198	20,556,198
Deferred compensation trust, shares	109,623	152,223
Treasury stock, shares	15,559,314	15,642,068