Summary of Information with Regard to Outstanding Warrants Issued in Connection with Equity and Debt Financing and Consultants (Detail)									12 Months Ended
	Dec. 31, 2013	Mar. 28, 2012	Dec. 30, 2010	Jul. 02, 2008	Feb. 04, 2008	May 31, 2003	Dec. 31, 2002	Aug. 31, 2001	Dec. 31, 2013 February 12, 2009 Series B-1 Transaction	Dec. 31, 2013 May 13, 2009 Series B-2 Transaction	Dec. 31, 2013 June 30, 2009 Series B-2 Transaction Warrant 5	Dec. 31, 2013 June 30, 2009 Series B-2 Transaction Warrant 6	Dec. 31, 2013 May 1, 2009 Consultant Warrants	Dec. 31, 2013 June 30, 2009 Consultant Warrants	Dec. 31, 2013 August 12, 2009 Series B-2 Transaction Warrant 5	Dec. 31, 2013 August 12, 2009 Series B-2 Transaction Warrant 6	Dec. 31, 2013 September 30, 2009 Series B-2 Transaction Warrant 5	Dec. 31, 2013 September 30, 2009 Series B-2 Transaction Warrant 6	Dec. 31, 2013 November 4, 2009 Series B-2 Transaction Warrant 5	Dec. 31, 2013 November 4, 2009 Series B-2 Transaction Warrant 6	Dec. 31, 2013 December 8, 2009 Series B-2 Transaction Warrant 5	Dec. 31, 2013 December 8, 2009 Series B-2 Transaction Warrant 6	Dec. 31, 2013 January 29, 2010 Series B-2 Transaction Warrant 5	Dec. 31, 2013 January 29, 2010 Series B-2 Transaction Warrant 6	Dec. 31, 2013 March 8, 2010 Series B-2 Transaction Warrant 5	Dec. 31, 2013 March 8, 2010 Series B-2 Transaction Warrant 6	Dec. 31, 2013 April 30, 2010 Series B-2 Transaction Warrant 5	Dec. 31, 2013 April 30, 2010 Series B-2 Transaction Warrant 6	Dec. 31, 2013 May 10, 2010 Series B-2 Transaction Warrant 5	Dec. 31, 2013 May 10, 2010 Series B-2 Transaction Warrant 6	Dec. 31, 2013 May Twenty Five Twenty Ten Consultant Warrants First Issuance	Dec. 31, 2013 May Twenty Five Twenty Ten Consultant Warrants Second Issuance	Dec. 31, 2013 June 15, 2010 Consultant Warrants	Dec. 31, 2013 December 9, 2010 Consultant Warrants	Dec. 31, 2013 December 30, 2010 Placement Agent Warrants	Dec. 31, 2013 March Twenty Eight Twenty Twelve Offering Warrants
Equity [Line Items]
Number Issued	6,035,229								1,200,000	600,000	33,333	333,333	6,250	40,000	50,000	200,000	54,166	216,666	51,666	206,666	54,167	216,667	54,167	216,667	55,834	223,334	51,667	206,667	95,000	380,000	14,584	7,500	100,000	33,334	500	1,333,061
Exercise Price			7.20	6.00	9.00	32.40	21.00	39.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	3.00	4.50	15.00	4.26	3.90	7.20	5.63
Exercisable Date									Feb. 12, 2009	May 13, 2009	Jun. 30, 2009	Jun. 30, 2009	May 01, 2009	Jun. 30, 2009	Aug. 12, 2009	Aug. 12, 2009	Sep. 30, 2009	Sep. 30, 2009	Nov. 04, 2009	Nov. 04, 2009	Dec. 08, 2009	Dec. 08, 2009	Jan. 29, 2010	Jan. 29, 2010	Mar. 08, 2010	Mar. 08, 2010	Apr. 30, 2010	Apr. 30, 2010	May 10, 2010	May 10, 2010	May 25, 2010	May 25, 2010	Jun. 15, 2010	Dec. 09, 2010	Dec. 30, 2010	Mar. 28, 2012
Expiration Date		May 02, 2016							Feb. 12, 2014	May 13, 2014	Jun. 30, 2014	Jun. 30, 2014	May 01, 2014	Jun. 30, 2014	Aug. 12, 2014	Aug. 12, 2014	Sep. 30, 2014	Sep. 30, 2014	Nov. 04, 2014	Nov. 04, 2014	Dec. 08, 2014	Dec. 08, 2014	Jan. 29, 2015	Jan. 29, 2015	Mar. 08, 2015	Mar. 08, 2015	Apr. 30, 2015	Apr. 30, 2015	May 10, 2015	May 10, 2015	May 25, 2014	May 25, 2014	Jun. 15, 2015	Dec. 09, 2015	Dec. 30, 2015	Mar. 28, 2017