CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2012	Dec. 31, 2011
CONSOLIDATED BALANCE SHEETS
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	67,479,518	63,928,082
Common stock, shares outstanding	67,479,518	63,928,082