Equity Plans and Share-Based Compensation (Share-based compensation cost by line item) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation cost	$ 170,446	$ 209,662	$ 538,365	$ 761,351
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation cost	58,898	82,623	183,725	252,800
Selling, general, administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation cost	$ 111,548	$ 127,039	$ 354,640	$ 508,551