Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Stockholders' equity:
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 0.004	$ 0.004
Common stock, shares authorized	168,750,000	168,750,000
Common stock, shares issued	36,709,890	36,776,624
Common stock, shares outstanding	36,709,890	36,776,624