Consolidated Balance Sheet (Parenthetical) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Statement of Financial Position [Abstract]
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.1	$ 0.1
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	61,877,589	54,253,550
Common stock, shares outstanding	61,782,180	54,228,170
Treasury stock, shares	95,409	25,380