Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Consolidated Balance Sheets [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, authorized shares	50,000,000	50,000,000
Preferred stock, issued shares
Preferred stock, outstanding shares
Common stock, par value	$ 0.01	$ 0.01
Common stock, authorized shares	150,000,000	150,000,000
Common stock, issued shares	77,843,883	66,071,424
Common stock, outstanding shares	77,843,883	66,071,424