Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Consolidated Balance Sheets [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
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	44,662,579	44,107,464
Common stock, shares outstanding	44,662,579	44,107,464
Treasury stock, shares issued	38,400	38,400