Arcion License Agreement (Details Textual) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Arcion License Agreement (Textual) [Abstract]
Common stock locking period	9 months
Milestone payments increased	$ 8,000,000
Research and development expense	12,032,168	4,711,610
US [Member]
Arcion License Agreement (Textual) [Abstract]
Potential Payments upon achieving certain pre-determined sales thresholds in the U.S	60,000,000
US [Member] | Minimum [Member]
Arcion License Agreement (Textual) [Abstract]
Milestone Sales	200,000,000
Milestone payment receivable from sublicensees	70,000,000
Arcion License Agreement [Member]
Arcion License Agreement (Textual) [Abstract]
Share issued to Arcion	500,516
Fair market value of unregistered shares issued	2,100,000
Potential payments upon filing and acceptance	2,500,000
Royalty term description	The Royalty Term for any given country is the later of (i) the first date there are no valid claims against any Arcion patent, (ii) expiration of patent exclusivity or (iii) tenth anniversary of the first commercial sale.
Research and development expense	2,100,000
Arcion License Agreement [Member] | Maximum [Member]
Arcion License Agreement (Textual) [Abstract]
Potential milestone payment upon FDA approval	35,000,000
Arcion License Agreement [Member] | Minimum [Member]
Arcion License Agreement (Textual) [Abstract]
Potential milestone payment upon FDA approval	$ 17,500,000