STATEMENTS OF CHANGES IN PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (USD $) In Thousands, except Share data	Total USD ($)	All Other USD ($)	Services USD ($)	Non-employee services USD ($)	Series A Preferred Stock USD ($)	Private Placement USD ($)	Employees USD ($)	Registered direct offering USD ($)	Employee Stock Option USD ($)	Securities Offering USD ($)	Collaboration Agreement USD ($)	Series A Preferred Stock USD ($)	Warrants to Purchase Series A Convertible Preferred Stock Warrants USD ($)	Warrants to Purchase Series A Convertible Preferred Stock Warrants Series A Preferred Stock USD ($)	Common Stock USD ($)	Common Stock All Other USD ($)	Common Stock Services USD ($)	Common Stock Private Placement USD ($)	Common Stock Registered direct offering USD ($)	Common Stock Employee Stock Option USD ($)	Common Stock Securities Offering USD ($)	Common Stock Collaboration Agreement USD ($)	Common Stock Non Employee Stock Options	Additional Paid-in Capital Common Stock USD ($)	Additional Paid-in Capital Common Stock All Other USD ($)	Additional Paid-in Capital Common Stock Services USD ($)	Additional Paid-in Capital Common Stock Non-employee services USD ($)	Additional Paid-in Capital Common Stock Private Placement USD ($)	Additional Paid-in Capital Common Stock Employees USD ($)	Additional Paid-in Capital Common Stock Registered direct offering USD ($)	Additional Paid-in Capital Common Stock Employee Stock Option USD ($)	Additional Paid-in Capital Common Stock Securities Offering USD ($)	Additional Paid-in Capital Common Stock Collaboration Agreement USD ($)	Additional Paid-in Capital Warrants USD ($)	Additional Paid-in Capital Warrants Non-employee services USD ($)	Additional Paid-in Capital Warrants Private Placement USD ($)	Deficit Accumulated During the Development Stage USD ($)
Beginning Balance at Sep. 09, 2003	$ 500																							$ 500
Beginning Balance (in shares) at Sep. 09, 2003															250,487
Net loss	(160)																																				(160)
Ending Balance at Dec. 31, 2003	340																							500													(160)
Ending Balance (in shares) at Dec. 31, 2003															250,487
Issuance of common stock (in shares)																2,254,389	256,749
Issuance of common stock		4,500	439													2	1								4,498	438
Fair value of options/warrants issued				264																							13								251
Net loss	(5,687)																																				(5,687)
Ending Balance at Dec. 31, 2004	(144)														3									5,449										251			(5,847)
Beginning Balance (in shares) at Dec. 31, 2004															2,761,625
Issuance of Series A convertible preferred stock (net of expenses of $1,340 and warrant cost of $1,683) (in shares)												4,197,946
Issuance of Series A convertible preferred stock (net of expenses of $1,340 and warrant cost of $1,683)	15,077											15,077
Issuance of common stock to EasyWeb Stockholders															189,922
Conversion of Series A convertible preferred stock @ $0.001 into $0.001 common stock on September 13, 2005 at an exchange ratio of .500974 (in shares)												(4,197,946)			4,197,823
Conversion of Series A convertible preferred stock @ $0.001 into $0.001 common stock on September 13, 2005 at an exchange ratio of .500974												(15,077)	(1,683)		4									15,073										1,683
Exercise of stock options (in shares)															98,622
Exercise of stock options	4																							4
Fair value of options/warrants issued				99	1,683									1,683													54								45
Net loss	(9,517)																																				(9,517)
Ending Balance at Dec. 31, 2005	7,202														7									20,580										1,979			(15,364)
Ending Balance (in shares) at Dec. 31, 2005															7,247,992
Stock-based compensation	2,777																							2,777
Issuance of common stock (in shares)																	25,000	7,991,256
Issuance of common stock			106			21,188												8								106		21,180
Exercise of warrants to purchase common stock (in shares)															2,806
Exercise of stock options (in shares)															5,845
Exercise of stock options	25																							25
Fair value of options/warrants issued	13,092																																	13,092
Net loss	(17,857)																																				(17,857)
Ending Balance at Dec. 31, 2006	26,533														15									44,668										15,071			(33,221)
Ending Balance (in shares) at Dec. 31, 2006															15,272,899
Stock-based compensation				120			1,318																				120		1,318
Issuance of common stock (in shares)																		5,910,049
Issuance of common stock						23,538												6										23,532
Exercise of stock options (in shares)															46,016
Exercise of stock options	36																							36
Issuance of restricted common stock (in shares)															70,000
Fair value of options/warrants issued	5,433																																	5,433
Net loss	(26,608)																																				(26,608)
Ending Balance at Dec. 31, 2007	30,370														21									69,674										20,504			(59,829)
Ending Balance (in shares) at Dec. 31, 2007															21,298,964
Stock-based compensation	1,600																							1,600
Issuance of restricted common stock (in shares)															586,500
Issuance of restricted common stock															1									(1)
Cancelled/ Forfeiture of unvested restricted common stock															(25,000)
Other																								1													(1)
Net loss	(25,231)																																				(25,231)
Ending Balance at Dec. 31, 2008	6,739														22									71,274										20,504			(85,061)
Ending Balance (in shares) at Dec. 31, 2008															21,860,464
Cummulative effect of a change in accounting principle - January 1, 2009 reclassification of warrants to warrant liabilities	(72)																																	(1,638)			1,566
Stock-based compensation	2,181																							2,181
Issuance of common stock and warrants (in shares)																		2,772,337	15,484,000
Issuance of common stock and warrants						4,595		22,338										3	15									385		22,323						4,207
Exercise of warrants to purchase common stock (in shares)															136,986
Exercise of warrants to purchase common stock	279																							279
Exercise of stock options (in shares)																				102,564
Exercise of stock options									73																						73
Issuance of restricted common stock (in shares)															1,400,500
Issuance of restricted common stock															2									(2)
Repurchase of shares of restricted common stock (in shares)															(103,823)
Repurchase of shares of restricted common stock	(380)																							(380)
Cancelled/ Forfeiture of unvested restricted common stock															(69,500)
Net loss	(7,649)																																				(7,649)
Ending Balance at Dec. 31, 2009	28,104														42									96,133										23,073			(91,144)
Ending Balance (in shares) at Dec. 31, 2009															41,583,528
Stock-based compensation	3,637																							3,637
Issuance of common stock (in shares)																			7,000,000
Issuance of common stock								32,804											7											32,797
Exercise of warrants to purchase common stock (in shares)															39,225
Exercise of warrants to purchase common stock	121																							360										(239)
Exercise of stock options (in shares)																				196,167
Exercise of stock options									225																						225
Issuance of restricted common stock (in shares)															115,000
Repurchase of shares of restricted common stock (in shares)															(416,108)
Repurchase of shares of restricted common stock	(1,668)														(1)									(1,667)
Cancelled/ Forfeiture of unvested restricted common stock															(51,250)
Expired warrants																								45										(45)
Net loss	(32,670)																																				(32,670)
Ending Balance at Dec. 31, 2010	30,553														48									131,530										22,789			(123,814)
Ending Balance (in shares) at Dec. 31, 2010															48,466,562
Stock-based compensation	2,759																							2,759
Issuance of common stock (in shares)																					11,040,000	6,063,161
Issuance of common stock										59,806	28,858										11	6										59,795	28,852
Exercise of warrants to purchase common stock (in shares)															2,377,571
Exercise of warrants to purchase common stock	12,701														2									21,766										(9,067)
Exercise of stock options (in shares)																				479,666			6,904
Exercise of stock options									981											1											980
Issuance of restricted common stock (in shares)															848,406
Issuance of restricted common stock															1									(1)
Repurchase of shares of restricted common stock (in shares)															(59,559)
Repurchase of shares of restricted common stock	(273)																							(273)
Cancelled/ Forfeiture of unvested restricted common stock															(16,667)
Expired warrants																								1,111										(1,111)
Net loss	(63,778)																																				(63,778)
Ending Balance at Dec. 31, 2011	$ 71,607														$ 69									$ 246,519										$ 12,611			$ (187,592)
Ending Balance (in shares) at Dec. 31, 2011															69,206,044