Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2016	Dec. 31, 2015
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.0005	$ 0.0005
Common stock, shares authorized	350,000,000	350,000,000
Common stock, shares issued	135,613,941	132,665,165
Common stock, shares outstanding	135,613,941	132,665,165