Stock Based Compensation (Details) (USD $)				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		3 Months Ended		6 Months Ended						3 Months Ended		6 Months Ended				6 Months Ended		6 Months Ended	12 Months Ended
	Feb. 05, 2014	Dec. 31, 2013	Oct. 15, 2013	Jun. 30, 2014 Employees [Member]	Jun. 30, 2013 Employees [Member]	Jun. 30, 2014 Employees and Directors [Member]	Jun. 30, 2014 Senior management [Member]	Jun. 30, 2013 Senior management [Member]	Jun. 30, 2014 Directors and nonemployees [Member]	Jun. 30, 2013 Directors and nonemployees [Member]	Jun. 30, 2014 Stock Options [Member]	Jun. 30, 2014 Stock Options [Member] Range $ 1.83 - 2.50 [Member]	Jun. 30, 2014 Stock Options [Member] Range $ 2.51 - 3.50 [Member]	Jun. 30, 2014 Stock Options [Member] Range $ 3.51 - 8.00 [Member]	Jun. 30, 2014 Stock Options [Member] Range $ 8.01 - 32.55 [Member]	Jun. 30, 2014 Stock Options [Member] Employees [Member]	Jun. 30, 2014 Stock Options [Member] Non employees [Member]	Jun. 30, 2014 Stock Options And Warrants [Member]	Jun. 30, 2013 Stock Options And Warrants [Member]	Jun. 30, 2014 Stock Options And Warrants [Member] Employees [Member]	Jun. 30, 2013 Stock Options And Warrants [Member] Employees [Member]	Jun. 30, 2014 Stock Options And Warrants [Member] Employees [Member]	Jun. 30, 2013 Stock Options And Warrants [Member] Employees [Member]	Jun. 30, 2014 Stock Options And Warrants [Member] Non-Employees [Member]	Jun. 30, 2013 Stock Options And Warrants [Member] Non-Employees [Member]	Jun. 30, 2014 Stock Options And Warrants [Member] Non-Employees [Member]	Jun. 30, 2013 Stock Options And Warrants [Member] Non-Employees [Member]	Jun. 30, 2014 Stock Options And Warrants [Member] Research and Development Expense [Member] Employees [Member]	Jun. 30, 2013 Stock Options And Warrants [Member] Research and Development Expense [Member] Employees [Member]	Jun. 30, 2014 Stock Options And Warrants [Member] Research and Development Expense [Member] Employees [Member]	Jun. 30, 2013 Stock Options And Warrants [Member] Research and Development Expense [Member] Employees [Member]	Jun. 30, 2014 Stock Options And Warrants [Member] Research and Development Expense [Member] Non-Employees [Member]	Jun. 30, 2013 Stock Options And Warrants [Member] Research and Development Expense [Member] Non-Employees [Member]	Jun. 30, 2014 Stock Options And Warrants [Member] Research and Development Expense [Member] Non-Employees [Member]	Jun. 30, 2013 Stock Options And Warrants [Member] Research and Development Expense [Member] Non-Employees [Member]	Jun. 30, 2014 Stock Options And Warrants [Member] General and Administrative Expense [Member] Employees [Member]	Jun. 30, 2013 Stock Options And Warrants [Member] General and Administrative Expense [Member] Employees [Member]	Jun. 30, 2014 Stock Options And Warrants [Member] General and Administrative Expense [Member] Employees [Member]	Jun. 30, 2013 Stock Options And Warrants [Member] General and Administrative Expense [Member] Employees [Member]	Jun. 30, 2014 Stock Options And Warrants [Member] General and Administrative Expense [Member] Non-Employees [Member]	Jun. 30, 2013 Stock Options And Warrants [Member] General and Administrative Expense [Member] Non-Employees [Member]	Jun. 30, 2014 Stock Options And Warrants [Member] General and Administrative Expense [Member] Non-Employees [Member]	Jun. 30, 2013 Stock Options And Warrants [Member] General and Administrative Expense [Member] Non-Employees [Member]	Jun. 30, 2014 Stock Options And Warrants [Member] Minimum [Member]	Jun. 30, 2013 Stock Options And Warrants [Member] Minimum [Member]	Jun. 30, 2014 Stock Options And Warrants [Member] Maximum [Member]	Jun. 30, 2013 Stock Options And Warrants [Member] Maximum [Member]	Jun. 30, 2014 Restricted Stock [Member]	Jun. 30, 2013 Restricted Stock [Member]	Jun. 30, 2014 Restricted Stock [Member]	Jun. 30, 2013 Restricted Stock [Member]	Jun. 30, 2014 Warrants [Member]	Dec. 31, 2013 Warrants [Member]	Jun. 30, 2014 2000 Long Term Incentive Plan [Member]	Jun. 30, 2014 2008 Stock Incentive Plan [Member]	Jun. 30, 2014 2008 Stock Incentive Plan [Member] Restricted Stock [Member] Senior management [Member]	Dec. 31, 2012 2008 Stock Incentive Plan [Member] Restricted Stock [Member] Senior management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation, shares subject to stock options (in shares)																																																						800,000	5,900,000
Expiration date																																																						Aug. 06, 2010
Share-based compensation, shares available for future grant (in shares)																																																						0	4,100,000
Share-based compensation arrangement by share-based payment award, fair value assumptions and methodology [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Method Used											Black-Scholes option-pricing model
Risk-free interest rate (in hundredths)																		1.92%	1.11%
Expected volatility (in hundredths)																																												87.00%	85.20%	89.60%	85.80%
Expected lives											6 years								6 years																									6 years		10 years
Expected dividend yield (in hundredths)																		0.00%	0.00%
Contractual term											10 years																																									10 years
Estimated annualized forfeiture rate (in hundredths)				12.00%	12.00%		2.00%	3.00%	0.00%	0.00%
Unrecognized compensation expense related to unvested stock options, granted						$ 4,300,000
Unrecognized compensation cost, recognized as expense over a weighted-average period						1 year 1 month 17 days
Number of Options (Employees and Non-Employees) [Abstract]
Outstanding at beginning of period (in shares)		100,000									6,395,736					6,228,593	167,143
Granted (in shares)											300,000					300,000	0
Forfeited (in shares)											(4,500)					(4,500)	0
Outstanding at end of period (in shares)		100,000									6,691,236					6,524,093	167,143
Options exercisable at end of period (in shares)											3,872,978					3,705,835	167,143
Weighted-Average Exercise Price Options [Abstract]
Outstanding at beginning of period (in dollars per share)											$ 3.11
Granted (in dollars per share)											$ 5.31
Forfeited (in dollars per share)											$ 2.35
Outstanding at end of period (in dollars per share)											$ 3.21
Options exercisable at end of period (in dollars per share)											$ 3.64
Number of Unvested Stock Options (Employees and Non-Employees) [Abstract]
Non-vested at beginning of period (in shares)											3,102,873					3,102,873	0
Granted, unvested stock options (in shares)											300,000					300,000	0
Vested (in shares)											(580,115)					(580,115)	0
Forfeited (in shares)											(4,500)					(4,500)	0
Non-vested at end of period (in shares)											2,818,258					2,818,258	0
Weighted average grant date fair value per share [Abstract]
Non-vested at beginning of period (in dollars per share)											$ 1.66
Granted, unvested stock options (in dollars per share)											$ 3.92
Vested (in dollars per share)											$ 1.74
Forfeited (in dollars per share)											$ 1.69
Non-vested at end of period (in dollars per share)											$ 1.88
Share-based compensation arrangement by share-based payment award, shares issued in period (in shares)																																																				25,000
Exercise price of warrants (in dollars per share)																																																				$ 5.60
Restricted stock granted (in shares)																																																								100,000	100,000
Restricted stock vested (in shares)																																																								50,000
Expected to vest over subsequent period (in shares)																																																								50,000
Value of restricted shares issued																																																								627,000	186,900
Total stock-based compensation expense resulting from stock options and warrants [Abstract]
Allocated employee and non-employee stock-based compensation expense, Total																				559,863	256,172	1,046,977	490,984	160,629	152,074	352,620	179,286	234,484	53,583	409,638	103,755	0	0	0	0	325,379	202,589	637,339	387,229	160,629	152,074	352,620	179,286					156,296	46,495	310,874	92,478
Share based compensation, shares authorized under significant ranges of outstanding stock option plans in period [Abstract]
Range of Exercise Prices, Lower Range (in dollars per share)												$ 1.83	$ 2.51	$ 3.51	$ 8.01
Range of Exercise Prices, Upper Range (in dollars per share)												$ 2.50	$ 3.50	$ 8.00	$ 32.55
Number of Options (in shares)											6,691,236	5,126,723	194,482	991,534	378,497
Weighted-Average Remaining Contractual Life											8 years 2 months 1 day	8 years 11 months 16 days	6 years 5 months 16 days	6 years 6 months 14 days	2 years 7 months 17 days
Weighted-Average Exercise Price (in dollars per share)											$ 3.21	$ 2.22	$ 2.79	$ 6.27	$ 8.86
Number of Options Exercisable (in shares)											3,872,978	2,649,036	154,720	690,725	378,497
Weighted-Average Remaining Contractual Life											8 years 2 months 1 day	8 years 11 months 16 days	6 years 5 months 16 days	6 years 6 months 14 days	2 years 7 months 17 days
Weighted-Average Exercise Price, Options Exercisable (in dollars per share)											$ 3.64	$ 2.16	$ 2.69	$ 6.70	$ 8.86
The aggregate intrinsic value of outstanding options											$ 12,620,000
Closing price of the common stock (in dollars per share)	$ 6.50		$ 2.25								$ 4.18
Warrants outstanding (in shares)																																																				7,894,791	8,324,609