Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($)  | 
Common Stock [Member]  | 
 Common Stock [Member]  
Employees and Directors [Member] 
 | 
Additional paid-in capital [Member]  | 
 Additional paid-in capital [Member]  
Employees and Directors [Member] 
 | 
Accumulated deficit [Member]  | 
 Accumulated deficit [Member]  
Employees and Directors [Member] 
 | 
Total  | 
Employees and Directors [Member]  | 
|---|---|---|---|---|---|---|---|---|
| Balance at Dec. 31, 2015 | $ 328,000 | $ 377,993,000 | $ (310,600,000) | $ 67,721,000 | ||||
| Balance (in shares) at Dec. 31, 2015 | 32,743,013 | |||||||
| Restricted common stock issued | $ 0 | $ 1,892,000 | $ 0 | $ 1,892,000 | ||||
| Restricted common stock issued (in shares) | 0 | |||||||
| Stock option compensation expense | $ 0 | 1,592,000 | 0 | 1,592,000 | ||||
| Net loss | 0 | 0 | (5,544,000) | (5,544,000) | ||||
| Balance at Mar. 31, 2016 | $ 328,000 | 381,477,000 | (316,144,000) | 65,661,000 | ||||
| Balance (in shares) at Mar. 31, 2016 | 32,743,013 | |||||||
| Balance at Dec. 31, 2015 | $ 328,000 | 377,993,000 | (310,600,000) | 67,721,000 | ||||
| Balance (in shares) at Dec. 31, 2015 | 32,743,013 | |||||||
| Common stock issued for $3.27 share for licenses | 2,452,000 | |||||||
| Net loss | (14,871,000) | |||||||
| Balance at Sep. 30, 2016 | $ 338,000 | 388,618,000 | (325,471,000) | 63,485,000 | ||||
| Balance (in shares) at Sep. 30, 2016 | 33,703,732 | |||||||
| Balance at Mar. 31, 2016 | $ 328,000 | 381,477,000 | (316,144,000) | 65,661,000 | ||||
| Balance (in shares) at Mar. 31, 2016 | 32,743,013 | |||||||
| Restricted common stock issued | $ 0 | $ 0 | 150,000 | 987,000 | 0 | 0 | 150,000 | 987,000 | 
| Restricted common stock issued (in shares) | 52,690 | 0 | ||||||
| Stock option compensation expense | $ 0 | 1,385,000 | 0 | 1,385,000 | ||||
| Net loss | 0 | 0 | (6,703,000) | (6,703,000) | ||||
| Balance at Jun. 30, 2016 | $ 328,000 | 383,999,000 | (322,847,000) | 61,480,000 | ||||
| Balance (in shares) at Jun. 30, 2016 | 32,795,703 | |||||||
| Restricted common stock issued | $ 0 | $ 241,000 | $ 0 | $ 241,000 | ||||
| Restricted common stock issued (in shares) | 0 | |||||||
| Common stock issued for $3.27 share for licenses | $ 8,000 | 2,444,000 | 0 | 2,452,000 | ||||
| Common stock issued for $3.27 share for licenses (in shares) | 750,000 | |||||||
| Common stock issued for an average of $6.44 share net of costs | $ 2,000 | 1,017,000 | 0 | 1,019,000 | ||||
| Common stock issued for an average of $6.44 share net of costs (in shares) | 158,029 | |||||||
| Stock option compensation expense | $ 0 | 917,000 | 0 | 917,000 | ||||
| Net loss | 0 | 0 | (2,624,000) | (2,624,000) | ||||
| Balance at Sep. 30, 2016 | $ 338,000 | $ 388,618,000 | $ (325,471,000) | $ 63,485,000 | ||||
| Balance (in shares) at Sep. 30, 2016 | 33,703,732 |