Nature of Operations (Detail Textuals 1) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Line of Credit Facility [Line Items]
Proceeds from issuance of public offerings held in February									$ 2,400,000
Net loss	(8,474)	(10,325)	(6,480)	(6,583)	(7,167)	(6,291)	(6,753)	(7,243)	(31,862,454)	(27,453,954)	(46,958,921)
Accumulated deficit	(786,646,266)				(754,783,812)				(786,646,266)	(754,783,812)
Total liabilities	24,429,699				26,620,334				24,429,699	26,620,334
Silicon Valley Bank | Line of Credit
Line of Credit Facility [Line Items]
Borrowing capacity under SVB loan facility	$ 15,000,000								$ 15,000,000