Note 3 - Fair Value Measurements (Detail) - Summary of changes in the fair value of the Company’s Level 3 fair value measurements: (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Beginning Balance	$ 4,105,659
Accrued Warrant Liability [Member]
Beginning Balance	7,285,959		25,350,733
Total (gains) or losses (realized/unrealized) included in earnings	(7,701,981)	[1],[2]	(19,821,787)	[1],[2]
Issuances	4,521,681		2,752,441
Settlements			(995,428)
Beginning Balance	4,105,659		7,285,959
Balance	(7,701,981,000,000)		(19,790,451,000,000)
Compensatory Stock Options Not Yet Issued [Member]
Beginning Balance	378,750		2,992,180
Total (gains) or losses (realized/unrealized) included in earnings	51,823	[1],[2]	(17,953)	[1],[2]
Issuances			378,750
Settlements	(430,573)		(2,974,227)
Beginning Balance			$ 378,750

[1] Realized & unrealized gains or losses related to the accrued warrant liability were included as change in value of accrued warrant liability.

[2] Realized gains or losses related to compensatory stock options were included in research & development expense and general & administrative expense.