CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Preferred stock, par value	$ 100	$ 100
Preferred stock, shares authorized	100,000	100,000
Preferred stock, issued	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	128,000,000	128,000,000
Common stock, shares issued	45,714,191	45,556,854
Treasury stock, shares	223,886	125,357