Capital Stock (Authorized, Issued and Reserved shares of common stock) (Detail) (USD $)							9 Months Ended
	Sep. 30, 2014	May 17, 2013	Sep. 30, 2014 Common Stock additional Purchase rights associated with May 2013 Private Placement [Member]	Sep. 30, 2014 Shares reserved under outstanding stock options and options available for grant [Member]	Sep. 30, 2014 Rights Associated With Employee Stock Purchase Plan [Member]	Sep. 30, 2014 Warrants with common stock additional purchase rights associated with May 2013 private placement [Member]	Sep. 30, 2014 Warrant One [Member]	Sep. 30, 2014 Warrant Two [Member]	Sep. 30, 2014 Warrant Three [Member]	Sep. 30, 2014 Warrant Four [Member]
Reserved for issuance	80,450,065		18,214,936	10,765,500	539,302	13,661,202	1,750,000	437,158	20,655,737	14,426,230
Strike Price		$ 0.2745				$ 0.2745	$ 1.3000	$ 0.2745	$ 0.2745	$ 0.2745
Expiry							Mar. 05, 2015	Jun. 29, 2017	May 17, 2020	Aug. 09, 2020