CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Mar. 31, 2012	Dec. 31, 2011
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	45,827,010	45,714,191
Treasury stock, shares	232,708	223,886