Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2012	Dec. 31, 2011	Dec. 31, 2010
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	100,000,000	100,000,000
Common stock, shares issued	38,314,617	38,066,830	35,280,000
Common stock, shares outstanding	36,596,617	36,348,830	33,562,000