Stock-Based Compensation - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended			162 Months Ended							12 Months Ended					2 Months Ended	12 Months Ended				1 Months Ended	12 Months Ended	1 Months Ended	12 Months Ended	1 Months Ended	12 Months Ended			12 Months Ended			1 Months Ended	12 Months Ended								1 Months Ended		12 Months Ended					1 Months Ended	12 Months Ended	1 Months Ended		12 Months Ended	1 Months Ended				12 Months Ended		1 Months Ended	12 Months Ended		1 Months Ended										12 Months Ended	1 Months Ended	12 Months Ended						1 Months Ended	12 Months Ended	1 Months Ended			12 Months Ended				1 Months Ended	12 Months Ended	1 Months Ended		12 Months Ended				12 Months Ended
	Feb. 28, 2009	Dec. 31, 2013 CompensationPlan	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 CompensationPlan	Feb. 25, 2008	Feb. 04, 2008	Jan. 31, 2003	Dec. 31, 2002	Dec. 31, 2001	Aug. 31, 2001	Dec. 31, 2011 Scenario 1	Dec. 31, 2011 Scenario 2	Dec. 31, 2013 Cashless	Dec. 31, 2012 Cashless	Dec. 31, 2011 Monte Carlo Option Pricing Model	Feb. 29, 2004 Stock Option	Dec. 31, 2012 Stock Option	Dec. 31, 2011 Stock Option	Dec. 31, 2003 Stock Option	Sep. 30, 2013 Stock Options	Sep. 30, 2013 Stock Options Amendment	Dec. 31, 2011 Restricted Stock	Mar. 31, 2002 Non Employee Board Member and Former Member of Audit Committee Second Consulting Agreement	Dec. 31, 2002 Non Employee Board Member and Former Member of Audit Committee Second Consulting Agreement	Jun. 30, 2003 Non Employee Board Member and Former Member of Audit Committee Third Consulting Agreement	Dec. 31, 2004 Non Employee Board Member and Former Member of Audit Committee Third Consulting Agreement	Dec. 31, 2003 Non Employee Board Member and Former Member of Audit Committee Third Consulting Agreement	Dec. 31, 2002 Non Employee Board Member and Former Member of Audit Committee Stock Option	Dec. 31, 2002 Non Employee Board Member and Former Member of Audit Committee Stock Option Second Consulting Agreement	Dec. 31, 2004 Non Employee Board Member and Former Member of Audit Committee Stock Options Third Consulting Agreement	Dec. 31, 2003 Non Employee Board Member and Former Member of Audit Committee Stock Options Third Consulting Agreement	Jan. 31, 2003 Board of Directors	Dec. 31, 2011 Board of Directors	Dec. 31, 2010 Board of Directors	Dec. 31, 2009 Board of Directors	Dec. 31, 2004 Board of Directors	Dec. 31, 2003 Board of Directors	Dec. 31, 2004 Board of Directors Stock Option	Dec. 31, 2003 Board of Directors Stock Option	Dec. 31, 2011 Board of Directors Restricted Stock	Nov. 30, 2005 Member of Scientific Advisory Board	May 31, 2003 Member of Scientific Advisory Board	Dec. 31, 2004 Member of Scientific Advisory Board	Dec. 31, 2003 Member of Scientific Advisory Board	Dec. 31, 2005 Member of Scientific Advisory Board Stock Option	Dec. 31, 2004 Member of Scientific Advisory Board Stock Option	Dec. 31, 2003 Member of Scientific Advisory Board Stock Option	Sep. 30, 2003 Board Member and Member of Scientific Advisory Board	Dec. 31, 2003 Board Member and Member of Scientific Advisory Board Stock Option	Oct. 31, 2003 Former Chief Financial Officer	Sep. 30, 2003 Former Chief Financial Officer	Dec. 31, 2003 Former Chief Financial Officer	Oct. 31, 2003 Former Chief Financial Officer Cashless	Oct. 31, 2003 Former Chief Financial Officer Stock Option	Apr. 30, 2004 Investor Relations Firm	Mar. 31, 2004 Investor Relations Firm	Dec. 31, 2005 Investor Relations Firm	Dec. 31, 2004 Investor Relations Firm	Mar. 31, 2004 Investor Relations Firm Stock Option	Dec. 31, 2003 Investor Relations Firm Stock Option Options Vested on December Thirty One Twenty Zero Three	Dec. 31, 2004 Investor Relations Firm Stock Option Options Vested on January and February Twenty Zero Four	Jun. 30, 2013 Consultant	Aug. 31, 2012 Consultant	May 31, 2012 Consultant	Nov. 15, 2011 Consultant	Mar. 31, 2009 Consultant	Feb. 28, 2009 Consultant	Apr. 30, 2008 Consultant	Mar. 31, 2008 Consultant	Dec. 31, 2007 Consultant	Mar. 31, 2006 Consultant	Dec. 31, 2011 Consultant	Mar. 31, 2006 Consultant Stock Option	Dec. 31, 2009 Consultant Stock Option	Dec. 31, 2008 Consultant Stock Option	Dec. 31, 2007 Consultant Stock Option	Dec. 31, 2011 Consultant Restricted Stock Scenario 2	Dec. 31, 2013 Minimum	Dec. 31, 2011 Minimum	Jun. 30, 2013 Minimum Consultant	Dec. 31, 2013 Maximum	Apr. 30, 2004 Maximum Investor Relations Firm	Mar. 31, 2004 Maximum Investor Relations Firm	Jun. 30, 2013 Maximum Consultant	Dec. 31, 2001 Consulting Agreement Non Employee Board Member and Former Member of Audit Committee	Dec. 31, 2003 Consulting Agreement Non Employee Board Member and Former Member of Audit Committee Stock Option	Dec. 31, 2002 Consulting Agreement Non Employee Board Member and Former Member of Audit Committee Stock Option	Dec. 31, 2001 Consulting Agreement Non Employee Board Member and Former Member of Audit Committee Stock Option	Oct. 31, 2001 Stock Incentive Plan Twenty Zero One	Dec. 31, 2013 Stock Incentive Plan Twenty Zero One	Oct. 31, 2001 Stock Incentive Plan Twenty Zero One Minimum	Oct. 31, 2001 Stock Incentive Plan Twenty Zero One Maximum	Dec. 31, 2013 Non Employee Director Stock Options Plan, Twenty Zero Three	Dec. 31, 2003 Non Employee Director Stock Options Plan, Twenty Zero Three	Dec. 31, 2013 Incentive Compensation Plan 2009	Feb. 28, 2009 Incentive Compensation Plan 2009	Dec. 31, 2012 Non Qualified Options Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share based compensation plans		3			3
Number of common stock for issuance upon exercise of grants																					103,158																																																																					833,334					166,667		3,333,334
Stock awards, vesting period																																																																																										3 years
Stock options expiration period																																																																																												3 years	10 years
Non-plan grants outstanding		3,348,705	3,539,961	3,091,474	3,348,705																																																																																						194,167			5,168				1,416,669
Stock awards, grant period																																																																																											10 years			10 years
Stock awards, available for future grant																																																																																																709,638
Non-plan stock option grants to employees and non-employees																																																																																																		1,477,379
Expected life		5 years 3 months 15 days	5 years 9 months 22 days		5 years 2 months 9 days											10 years																																																															5 years			10 years
Expected dividend yield used in the option valuation model		0.00%	0.00%		0.00%
Stock Option expected to vest only upon achievement of certain market conditions				166,668								83,334	83,334
Total fair value of options vested		$ 2,406,000	$ 2,447,000		$ 15,473,000							$ 5,000,000,000	$ 10,000,000,000
Unrecognized compensation cost		4,522,000			4,522,000											1,006,000
Unrecognized compensation cost, recognition period		4 years 6 months														5 years 6 months
Annualized volatility		115.00%	116.00%		119.00%											110.00%
Annualized risk free rate		1.17%	0.90%		1.68%											3.50%
Common stock price		$ 8.08			$ 8.08	$ 2.40	$ 3.54	$ 6.00	$ 21.00	$ 13.68	$ 13.68																																																																					$ 9.00
Weighted-average grant-date fair values of options granted		$ 3.17	$ 1.77
Unvested option		1,256,735	1,472,051		1,256,735
Number of stock options exercised		213,008	51,830											173,669	90,253																																							8,334
Stock options exercised		378,000	96,000
Proceeds from exercise of stock options		271,000	0
Number of shares issued in the conversion of options in a noncash transaction		81,591	51,830																																																2,772
Intrinsic value of options exercised		1,498,000	162,000		3,222,000
Number of options vested	83,334	614,041	595,420														10,000			2,500				334	3,334	334																															834	2,500	7,500								833			833		834
Number of options granted																								4,000		4,000							16,667										1,667						4,167			16,667																																		33,334
Exercise price of stock options		$ 3.89	$ 2.13																					$ 21.00									$ 21.00									$ 15.66	$ 21.00						$ 24.30		$ 17.82	$ 24.30				$ 30.96	$ 34.80						$ 3.97					$ 0	$ 2.64		$ 3.78	$ 22.50														$ 21.00
Stock option, fair market value																																																																																						239,000
Common stock price per share																								$ 12.96		$ 21.00							$ 16.80									$ 8.10	$ 16.80						$ 14.64						$ 26.70													$ 0.72	$ 2.34		$ 2.76	$ 13.20									$ 3.97				$ 7.25	$ 13.68
Stock-based compensation expense		3,789,000	2,792,000		16,163,000																									41,000	17,000	40,000							51,000	193,000	18,000					7,000	5,000	13,000		122,000	40,000		74,000					14,000	67,000		29,000	23,000	173,000											33,000	24,000	15,000	2,000	110,000									71,000	64,000	147,000
Number of options granted per month																								334
Stock option, fair market value																								11,000		33,000							156,000										16,000
Deferred compensation																													11,000
Fair value adjustments of unvested options																											(2,000)	21,000									4,000	82,000						2,000	6,000
Options vesting rate, vested immediately																																	33.33%										50.00%
Stock option issued																																										834																10,000		4,167			25,000					33,334	8,000		834	2,500
Number of options issuable as services are performed																																																																																			10,000	16,667
Number of options vest per month																																																								834
Extension of exercise period																		90 days	90 days
Additional stock-based compensation expense			271,000	63,000																		930,000
Common stock options granted, shares																																																																4,348	7,000
Fair market value of shares																																																																10,000	16,000
Stock options expiration period																						3 months
Stock option vested date																																																															2013-08
Restricted common stock granted		5,000	1,379,739																																	416,670
Restricted common stock vested																							46,876											390,628	26,042
Restricted shares, value																																				$ 450,000																														$ 113,000
Restricted shares, value per share																																				$ 1.08																														$ 5.40
Restricted common stock issued																							20,834																																																		20,834