Consolidated Statements of Changes in Stockholders' Equity (USD $) In Thousands, except Share data	Total	Series A Convertible Preferred Stock	Series D Convertible Preferred Stock	Series B Convertible Preferred Stock	Series E Convertible Preferred Stock	Convertible preferred stock	Convertible preferred stock Series A Convertible Preferred Stock	Convertible preferred stock Series D Convertible Preferred Stock	Convertible preferred stock Series B Convertible Preferred Stock	Convertible preferred stock Series E Convertible Preferred Stock	Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Series B Convertible Preferred Stock	Treasury Stock	Accumulated Deficit
Beginning Balances at Mar. 31, 2011	$ 15,507					$ 52,850					$ 86	$ 4,026			$ (41,455)
Beginning Balances (in shares) at Mar. 31, 2011						47,398,240					8,571,573
Exercise of warrants to purchase convertible preferred stock (in Shares)							9,389
Issuance of convertible preferred stock for cash (net of issuance costs) (in shares)								9,007,678
Issuance of convertible preferred stock for cash (net of issuance costs)			31,946					31,946
Exercise of warrants to purchase convertible preferred stock		10					10
Stock-based compensation and warrant expense	660											660
Issuance of common stock upon exercise of options (in shares)											539,673
Issuance of common stock upon exercise of options	158										5	153
Net income (loss)	(11,944)														(11,944)
Ending Balances at Mar. 31, 2012	36,337					84,806					91	4,839			(53,399)
Ending Balances (in shares) at Mar. 31, 2012						56,415,307					9,111,246
Exercise of warrants to purchase convertible preferred stock (in Shares)							568,073		357,978
Issuance of convertible preferred stock for cash (net of issuance costs) (in shares)										2,500,000
Issuance of convertible preferred stock for cash (net of issuance costs)					17,344					17,344
Exercise of warrants to purchase convertible preferred stock		606		165			606		267				(102)
Exercise of warrants to purchase common stock (in shares)											21,688
Exercise of warrants to purchase common stock	34										10	24
Stock-based compensation and warrant expense	1,110											1,110
Issuance of common stock upon exercise of options (in shares)											2,158,928
Issuance of common stock upon exercise of options	864										22	842
Other (in shares)														(17,640)
Other	(12)													(12)
Net income (loss)	(4,238)														(4,238)
Ending Balances at Dec. 31, 2012	52,210					103,023					123	6,713		(12)	(57,637)
Ending Balances (in shares) at Dec. 31, 2012						59,841,358					11,291,862			(17,640)
Exercise of warrants to purchase convertible preferred stock (in Shares)							207,339
Exercise of warrants to purchase convertible preferred stock		221					221
Exercise of warrants to purchase common stock (in shares)											239,469
Exercise of warrants to purchase common stock	150										2	148
Stock-based compensation and warrant expense	6,490											6,490
Issuance of common stock upon exercise of options (in shares)	2,232,969										2,232,969
Issuance of common stock upon exercise of options	1,715										23	1,692
Other (in shares)											(17,640)			17,640
Other											(10)	(2)		12
Net income (loss)	7,308														7,308
Ending Balances at Dec. 31, 2013	$ 68,094					$ 103,244					$ 138	$ 15,041			$ (50,329)
Ending Balances (in shares) at Dec. 31, 2013						60,048,697					13,746,660