Stockholders' Equity (Details Textual) (USD $)	0 Months Ended		12 Months Ended															12 Months Ended				0 Months Ended		9 Months Ended		12 Months Ended					0 Months Ended							0 Months Ended		9 Months Ended	12 Months Ended	9 Months Ended			1 Months Ended	9 Months Ended		0 Months Ended			9 Months Ended			0 Months Ended		9 Months Ended	0 Months Ended							9 Months Ended		12 Months Ended										9 Months Ended	0 Months Ended
	Feb. 17, 2012	Jan. 19, 2012	Dec. 31, 2013	Dec. 31, 2012	Apr. 10, 2012	Dec. 31, 2011	May 31, 2010	Dec. 31, 2013 Series C-1 Convertible Preferred Stock [Member]	Dec. 31, 2012 Series C-1 Convertible Preferred Stock [Member]	May 26, 2010 Series C-1 Convertible Preferred Stock [Member]	Dec. 31, 2013 Series F Convertible Preferred Stock [Member]	Dec. 31, 2012 Series F Convertible Preferred Stock [Member]	Dec. 31, 2013 Series C-2 Convertible Preferred Stock [Member]	Dec. 31, 2012 Series C-2 Convertible Preferred Stock [Member]	May 26, 2010 Series C-2 Convertible Preferred Stock [Member]	Dec. 31, 2013 Series D-1 Convertible Preferred Stock [Member]	Dec. 31, 2012 Series D-1 Convertible Preferred Stock [Member]	Dec. 31, 2013 Research and development [Member]	Dec. 31, 2012 Research and development [Member]	Dec. 31, 2013 General and administrative [Member]	Dec. 31, 2012 General and administrative [Member]	Sep. 24, 2013 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2013 Restricted Stock Units (RSUs) [Member]	Sep. 30, 2013 Restricted Stock Units (RSUs) [Member] Research and development [Member]	Sep. 30, 2013 Restricted Stock Units (RSUs) [Member] General and administrative [Member]	Dec. 31, 2013 Restricted Stock [Member] Research and development [Member]	Dec. 31, 2013 Restricted Stock [Member] General and administrative [Member]	Dec. 31, 2013 1994 Plan [Member]	Dec. 31, 2013 2004 Plan [Member]	May 31, 2004 2004 Plan [Member]	May 31, 2004 2004 Plan [Member] Maximum [Member]	Dec. 31, 2013 2010 Plan [Member]	Oct. 31, 2012 2010 Plan [Member]	Jul. 31, 2012 2010 Plan [Member]	May 31, 2012 2010 Plan [Member]	Sep. 30, 2011 2010 Plan [Member]	Aug. 31, 2010 2010 Plan [Member]	Sep. 24, 2013 2013 Plan [Member]	Dec. 31, 2013 2013 Plan [Member]	Sep. 30, 2013 Common Stock [Member]	Dec. 31, 2013 Common Stock [Member]	Sep. 30, 2013 Common Stock [Member] Series C-1 Convertible Preferred Stock [Member]	Sep. 30, 2013 Common Stock [Member] Series D-1 Convertible Preferred Stock [Member]	Sep. 30, 2013 Common Stock [Member] Restricted Stock Units (RSUs) [Member]	Apr. 30, 2013 Common Stock [Member] Restricted Stock [Member]	Sep. 30, 2013 Common Stock [Member] Restricted Stock [Member]	Sep. 30, 2013 Private Placement [Member] Common Stock [Member] Restricted Stock [Member]	Apr. 10, 2012 One-year Anniversary Date of Grant [Member]	Apr. 10, 2012 Monthly, Following One-year Anniversary Date of Grant [Member]	Jan. 14, 2014 Subsequent Event [Member]	Sep. 30, 2013 President And Chief Executive Officer [Member] Common Stock [Member]	Sep. 30, 2013 Director [Member] Common Stock [Member]	Sep. 30, 2013 Director [Member] Common Stock [Member] Restricted Stock [Member]	Apr. 10, 2012 Director [Member] Quarterly [Member]	Sep. 24, 2013 Officer [Member] Restricted Stock [Member]	Sep. 30, 2013 Officer [Member] Common Stock [Member] Restricted Stock [Member]	Sep. 24, 2013 Officer [Member] Earlier of First Draft Approval or Stock Trading for 20 Consecutive Days at 10.50 Dollars Per Share [Member] Restricted Stock [Member]	Sep. 24, 2013 Officer [Member] Stock Trading for 20 Consecutive Days at 7 Dollars Per Share [Member] Restricted Stock [Member]	Sep. 24, 2013 Officer [Member] Stock Trading for 20 Consecutive Days at 12.50 Dollars Per Share [Member] Restricted Stock [Member]	Sep. 24, 2013 Officer [Member] January 20, 2015 Vesting [Member] Restricted Stock [Member]	Sep. 24, 2013 Officer [Member] January 20, 2016 Vesting [Member] Restricted Stock [Member]	Sep. 24, 2013 Officer [Member] Stock Trading for 20 Consecutive Days at 15 Dollars Per Share [Member] Restricted Stock [Member]	Sep. 24, 2013 Officer [Member] Stock Trading for 20 Consecutive Days at 17.50 Dollars Per Share [Member] Restricted Stock [Member]	Sep. 30, 2013 Employees [Member] Common Stock [Member]	Sep. 30, 2013 Employees [Member] Common Stock [Member] Restricted Stock [Member]	Dec. 31, 2013 First Employee [Member] Restricted Stock [Member]	Dec. 31, 2013 First Employee [Member] January 20, 2015 Vesting [Member] Restricted Stock [Member]	Dec. 31, 2013 First Employee [Member] NASDAQ Listing or January 20, 2016 [Member] Restricted Stock [Member]	Dec. 31, 2013 First Employee [Member] Monthly, Starting January 20, 2014 [Member] Restricted Stock [Member]	Dec. 31, 2013 Second Employee [Member] Restricted Stock [Member]	Dec. 31, 2013 Second Employee [Member] Monthly, Starting January 14, 2015 [Member] Restricted Stock [Member]	Dec. 31, 2013 Second Employee [Member] Earlier of NASDAQ Listing or January 14, 2015, in No Event Earlier than January 14, 2014 [Member] Restricted Stock [Member]	Dec. 31, 2013 Second Employee [Member] January 14, 2015 Vesting [Member] Restricted Stock [Member]	Dec. 31, 2013 Third Employee [Member] January 1, 2014 Vesting [Member] Restricted Stock [Member]	Dec. 31, 2013 Third Employee [Member] Monthly, Starting January 1, 2014 [Member] Restricted Stock [Member]	Sep. 30, 2013 Management [Member] Private Placement [Member] Common Stock [Member] Restricted Stock [Member]	Apr. 10, 2012 Chief Executive Officer and an Employee [Member] One-year Anniversary Date of Grant [Member]	Apr. 10, 2012 Chief Executive Officer and an Employee [Member] Monthly, Following One-year Anniversary Date of Grant [Member]
Reverse Stock Splits [Abstract]
Reverse stock split ratio	0.01	0.01																																																0.02
Preferred Stock
Preferred stock, shares authorized			8,000,000					11,000	11,000		10,000	10,000	0	22,000		0	5,134
Preferred stock, par value			$ 0.0001					$ 0.0001	$ 0.0001	$ 0.0001	$ 0.0001	$ 0.0001	$ 0.0001	$ 0.0001	$ 0.0001	$ 0.0001	$ 0.0001
Preferred stock, shares issued								7,016	5,792		3,250	0	0	500		0	4,615
Preferred stock, shares outstanding								7,016	5,792		3,250	0	0	500		0	4,615
Warrants
Outstanding warrants			0
Stock Option Plans
Common stock, shares authorized			12,000,000,000	12,000,000,000																										12					23,768		19
Common stock, shares outstanding			54,000	11,844,627		18																							0			0
Common Stock, issuable shares																												0	0			0							440,441
Award vesting rights, expiration period			10 years																												10 years																								7 years
Common stock offered for purchase to employee					11,844,609		11
Increase in the shares of common stock authorized for issuance under the Employee Stock Purchase Plan																																				320
Maximum authorized shares																																				340		42,920
Maximum percentage of the base salary of which an employee can purchase common stock																																10.00%
Additional common shares authorized																																	2,410	956
Options granted at exercise price					$ 3.00
Award vesting rights, percentage																																																25.00%	2.08%								28.57%	14.29%	14.29%	7.14%	7.14%	14.29%	14.29%				25.00%	25.00%	50.00%		50.00%	25.00%	25.00%	25.00%	75.00%		25.00%	2.08%
Award vesting rights, minimum share price for consecutive 20 days																																																									$ 10.50	$ 7.00	$ 12.50			$ 15.00	$ 17.50
Award vesting rights, consecutive period of minimum share price																																																							20 days
Automatic annual increase based on outstanding shares of Common Stock as of the last day of the previous year end, percent																																						10.00%
Percentage of options granted at exercise price			100.00%
Period of share-based payment awards																																																						1 year												24 months				24 months
Weighted average grant-date fair values of options granted			$ 6.00
Unrecognized compensation costs related to non-vested stock option awards			$ 314,000
Service period of share compensation			3 years 9 months 12 days																							24 months	35 months
Stock option exercises			0	0
Forfeitures estimated			0	0
Stockholders' Equity (Textual) [Abstract]
Stock issued during period																																								4,119,058	1,929,000	165,652	201,914	40,000	4,000	4,000	1,928,635				16,000	6,000	79,622			1,327,048								14,000	336,185											1,742,857
Award vesting rights																																													The shares were issued under the 2010 Plan and vest quarterly beginning on January 14, 2013. These shares were subject to a reacquisition right if the services of the holder are terminated during the vesting period.
Share-based compensation expense			12,373,000	8,604,000														992,000	805,000	11,381,000	7,799,000			157	52,000	95,000	4,464,000
Unamortized share-based compensation expense																							$ 0			$ 1,900,000	$ 13,700,000
Restricted stock units, cancellations																						207,502