Note 9 - Stockholders' Equity (Detail) (USD $)	1 Months Ended	3 Months Ended	12 Months Ended								1 Months Ended		1 Months Ended			1 Months Ended				1 Months Ended	3 Months Ended	6 Months Ended		1 Months Ended		1 Months Ended	9 Months Ended	1 Months Ended		1 Months Ended		1 Months Ended			1 Months Ended
	Aug. 31, 2012	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Jun. 30, 2012	Sep. 30, 2009	Jan. 31, 2003	Jan. 31, 2011 Aggregate Proceeds of 10 Million Dollars [Member] January 2011 Preferred Stock Offering [Member]	Jan. 31, 2011 Minimum 4 Dollar Share Price [Member] January 2011 Preferred Stock Offering [Member]	Jan. 31, 2011 Aggregate Proceeds of 4 Million Dollars [Member] January 2011 Preferred Stock Offering [Member]	Jan. 31, 2011 Greater Than 6 Dollar Share Price [Member] January 2011 Preferred Stock Offering [Member]	Jan. 31, 2011 Director [Member] January 2011 Preferred Stock Offering [Member]	Jun. 02, 2011 Director [Member] June 2, 2011 Private Placement Offering [Member]	Jul. 31, 2011 Registered Offering [Member] July 25, 2011 Register Direct and Private Placement Offerings [Member]	Jul. 31, 2011 Private Offering [Member] July 25, 2011 Register Direct and Private Placement Offerings [Member]	Jan. 31, 2011 Common Stock [Member] January 2011 Preferred Stock Offering [Member]	Jan. 31, 2011 Preferred Stock [Member] January 2011 Preferred Stock Offering [Member]	Jun. 30, 2010 Committed Equity Financing Facility [Member]	Jun. 30, 2011 Committed Equity Financing Facility [Member]	Dec. 31, 2010 Committed Equity Financing Facility [Member]	Dec. 31, 2011 Committed Equity Financing Facility [Member]	Jan. 31, 2011 Convertible Preferred Stock [Member] January 2011 Preferred Stock Offering [Member]	Jan. 31, 2011 Dominick and Dominick LLC [Member] January 2011 Preferred Stock Offering [Member]	Jan. 31, 2011 January 2011 Preferred Stock Offering [Member]	Sep. 30, 2011 January 2011 Preferred Stock Offering [Member]	Jun. 30, 2011 June 2, 2011 Private Placement Offering [Member]	Jun. 02, 2011 June 2, 2011 Private Placement Offering [Member]	Jul. 31, 2011 July 6, 2011 Registered Direct Offering [Member]	Jul. 06, 2011 July 6, 2011 Registered Direct Offering [Member]	Jul. 31, 2011 July 25, 2011 Register Direct and Private Placement Offerings [Member]	Jul. 25, 2011 July 25, 2011 Register Direct and Private Placement Offerings [Member]	Jul. 20, 2011 July 25, 2011 Register Direct and Private Placement Offerings [Member]	Dec. 31, 2011 December 6, 2011 Private Placement Offering [Member]	Dec. 06, 2011 December 6, 2011 Private Placement Offering [Member]
Shelf Registration Statement, Amount	$ 75,000,000					$ 50,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period (in Shares)			10.2
Proceeds from Exercise of Warrants and Options				400,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in Shares)			3,804,868	156,866	0		51,370
Preferred Stock, Shares Issued (in Shares)																								5,000
Preferred Stock, Dividend Rate, Percentage																								8.00%
Preferred Stock, Par or Stated Value Per Share (in Dollars per share)																										$ 1,000
Common Stock Shares Available for Purchase from Issued Warrants (in Shares)								1,009,076																		2,083,333					628,668		914,305	512,412		3,243,244
Common Stock Shares Per Warrant (in Shares)																										416.6666					0.3		0.30	0.40
Class of Warrant or Right, Exercise Price of Warrants or Rights (in Dollars per Item)			3.37	3.15	5.24	5.24		5.24										3.25	1,000										2.77		3.13	4.22				2.36
Unit Price (in Dollars per share)														$ 1,197.92	$ 2.895											$ 1,000			$ 2.65		$ 3.1675		$ 4.2575	$ 4.27		$ 2.3125
Preferred Stock, Redemption Price Per Share (in Dollars per share)																									$ 1,000	$ 2.40
Preferred Stock Shares Available for Purchase from Issued Warrants (in Shares)																										350
Proceed From Securities Offering																12,975,506	5,469,998									5,100,000				6,637,688					15,000,000
Common Stock, Par or Stated Value Per Share (in Dollars per share)			$ 0.01	$ 0.01						$ 4.00		$ 6.00
Proceeds from Issuance of Common Stock (in Dollars)				48,082,025	2,484,536						10,000,000		4,000,000									3.4
Professional Fees																					274,806					675,918	598,065
Amortization of Financing Costs																											77,853
Common Stock, Shares, Issued (in Shares)			37,967,708	33,899,057				2,018,153	253,691																				3,218,612	2,095,560			3,047,682	1,281,031		6,486,488
Warrant Premium (in Dollars per share)																													$ 0.125							$ 0.125
Proceeds from Issuance of Private Placement																												8,600,000
Proceed From Securities Offering, Net																														6,000,000		17,000,000
Proceeds from Warrant Exercises (in Dollars)		300,000	10,106,557	428,337																										2,000,000		6,000,000			7,500,000
Warrants Issued Expiration Period																														5 years		5 years			5 years
Committed Value of Common Stock Shares for Future Purchase																				15,000,000
Common Stock Sale Limit Under CEFF (in Shares)																				2,404,434
Percent of Outstanding Shares																				20.00%
Percentage Limit of Ownership by SCBV																				9.90%
Stock Issued During Period, Value, New Issues																				40,000
Stock Issued During Period, Shares, New Issues (in Shares)																						1,340,514
																						$ 332,000	$ 274,806