Equity Plans and Share-Based Compensation (Share-based compensation cost by line item) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation cost	$ 201,346	$ 289,318	$ 551,688	$ 1,101,292
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation cost	68,012	40,951	170,177	227,042
Selling, general, administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation cost	$ 133,334	$ 248,367	$ 381,511	$ 874,250