Stockholders' Equity (Details Textual) (USD $)	3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	1 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended	1 Months Ended	6 Months Ended					1 Months Ended		6 Months Ended		1 Months Ended		6 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	May 12, 2013	Jun. 30, 2013 General and administrative	Jun. 30, 2012 General and administrative	Jun. 30, 2013 General and administrative	Jun. 30, 2012 General and administrative	Jun. 30, 2013 Research and development	Jun. 30, 2012 Research and development	Jun. 30, 2013 Research and development	Jun. 30, 2012 Research and development	Jun. 30, 2013 Restricted Stock Research and development	Jun. 30, 2013 Restricted Stock Research and development	Jun. 30, 2013 Restricted Stock Units (RSUs)	Jun. 30, 2013 Restricted Stock Units (RSUs) General and administrative	Jun. 30, 2013 Restricted Stock Units (RSUs) General and administrative	Jun. 30, 2013 Restricted Stock Units (RSUs) Research and development	Jun. 30, 2013 Restricted Stock Units (RSUs) Research and development	Apr. 30, 2013 Common Stock	Jun. 30, 2013 Common Stock	Jun. 30, 2013 Common Stock General and administrative	Jun. 30, 2013 Common Stock General and administrative	Jun. 30, 2013 Common Stock Research and development	Jun. 30, 2013 Common Stock Research and development	Apr. 30, 2013 Common Stock Restricted Stock	Jun. 30, 2013 Common Stock Restricted Stock	Jun. 30, 2013 Common Stock Restricted Stock Units (RSUs)	Jun. 30, 2013 Common Stock President And Chief Executive Officer	Jun. 30, 2013 Common Stock Director	Jun. 30, 2013 Common Stock Employees	Jun. 30, 2013 Series C-1 Preferred	May 25, 2013 Series C-1 Preferred	Jun. 30, 2013 Series C-1 Preferred	Jun. 30, 2013 Series C-1 Preferred Common Stock	Jun. 30, 2013 Series C-2 Preferred	May 25, 2013 Series C-2 Preferred	Jun. 30, 2013 Series D-1 Preferred	Dec. 31, 2012 Series D-1 Preferred	Jun. 30, 2013 Series D-1 Preferred Common Stock	Jun. 30, 2013 Series D-2 Preferred
Stockholders' Equity (Textual) [Abstract]
Preferred stock, shares authorized	8,000,000		8,000,000																														11,000		11,000		22,000		5,134	5,134		10,868
Preferred stock, par value	$ 0.0001		$ 0.0001																																				$ 0.0001	$ 0.0001
Preferred stock, shares issued																																	6,214		6,214		530		4,568	4,615
Preferred stock, shares outstanding																																	6,214		6,214		530		4,568	4,615
Preferred stock dividends, shares																																		433				30
Preferred stock dividends, shares accrued																																	98				98
Preferred stock converted into common stock																																			11				47
Exercise price of Warrants granted	$ 21,500		$ 21,500
Issued warrants to purchase shares	390		390
Term of common stock warrants			5 years
Shares of common stock issued																					1,800,000	16,218,845					200,000	200,000	1,460,000	800,000	300,000	700,000				2,663,114					10,095,731
Shares of common stock vested																					1,800,000
Share-based compensation expense	$ 2,143,000	$ 2,710,000	$ 5,609,000	$ 2,710,000		$ 1,892,000	$ 2,462,000	$ 4,962,000	$ 2,462,000	$ 251,000	$ 248,000	$ 647,000	$ 248,000	$ 7,000	$ 7,000		$ 0	$ 52,000	$ 53	$ 110			$ 112,000	$ 121,000	$ 32,000	$ 35,500
Recognized weighted average period			2 years 7 months 6 days												7 months
Unamortized share-based compensation expense	22,100,000		22,100,000
Restricted stock, award vesting rights																											The shares were issued under the 2010 Plan and vest quarterly beginning on January 14, 2013. These shares are subject to a reacquisition right if the services of the holder are terminated during the vesting period.
Unamortized share-based compensation expense														$ 9,000	$ 9,000	$ 544
Stockholders' Equity (Additional Textual) [Abstract]
Warrants Expired					390
Outstanding warrants	0		0