|
Common Stock - Additional Information (Detail) (USD $)
|
6 Months Ended | 1 Months Ended | 6 Months Ended | 1 Months Ended | 6 Months Ended | 12 Months Ended | 6 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | 3 Months Ended | 6 Months Ended | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Jun. 30, 2014
|
Jun. 30, 2013
|
Apr. 30, 2013
2013 ATM [Member]
|
Jun. 30, 2013
Common Stock [Member]
|
Jun. 30, 2014
Restricted Stock [Member]
|
Feb. 28, 2014
Executive Vice Chairman [Member]
|
Dec. 19, 2013
Executive Vice Chairman [Member]
|
Feb. 20, 2014
Executive Vice Chairman [Member]
|
Jun. 30, 2014
Executive Vice Chairman [Member]
Share-based Compensation Award, Tranche One [Member]
|
Jun. 30, 2014
Executive Vice Chairman [Member]
Share-based Compensation Award, Tranche Two [Member]
|
Jun. 30, 2014
Executive Vice Chairman [Member]
Share-based Compensation Award, Tranche Three [Member]
|
Jun. 30, 2014
Executive Vice Chairman [Member]
Restricted Stock [Member]
|
Dec. 31, 2013
Executive Vice Chairman [Member]
Restricted Stock [Member]
|
Jun. 30, 2014
Director [Member]
|
Feb. 20, 2014
Director [Member]
|
Jun. 30, 2014
Board Of Directors [Member]
|
Feb. 20, 2014
Board Of Directors [Member]
|
Jun. 30, 2014
Research and Development Expense [Member]
|
Jun. 30, 2013
Research and Development Expense [Member]
|
Jun. 30, 2014
Research and Development Expense [Member]
|
Jun. 30, 2013
Research and Development Expense [Member]
|
Mar. 31, 2014
General and Administrative Expense [Member]
|
Mar. 31, 2013
General and Administrative Expense [Member]
|
Jun. 30, 2014
General and Administrative Expense [Member]
|
Jun. 30, 2013
General and Administrative Expense [Member]
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||||||||||||||||||||||||
| Stock Issued During Period, Value, Other | $ 45,000,000 | ||||||||||||||||||||||||
| Professional Fees | 32,000 | ||||||||||||||||||||||||
| Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options | 1,900,000 | ||||||||||||||||||||||||
| Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options | 17,500,000 | ||||||||||||||||||||||||
| Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition | 1 year | 3 years 6 months | |||||||||||||||||||||||
| Stock Issued During Period Shares warrants Exercised | 73,011 | 340 | |||||||||||||||||||||||
| Cash Less Exercise Of Warrants | 143,429 | ||||||||||||||||||||||||
| Warrants Exercise Price | $ 5.18 | ||||||||||||||||||||||||
| Allocated Share-based Compensation Expense | 300,000 | 600,000 | 600,000 | 1,400,000 | 1,200,000 | 700,000 | 2,000,000 | 1,400,000 | |||||||||||||||||
| Officers Compensation | 28,275 | ||||||||||||||||||||||||
| Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period | 3,958,692 | 1,979,346 | 30,000 | 50,000 | |||||||||||||||||||||
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value | 10,600,000 | 3,800,000 | 500,000 | ||||||||||||||||||||||
| Share Price | $ 1.93 | $ 2.69 | $ 2.69 | $ 2.69 | |||||||||||||||||||||
| Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage | 16.67% | 10.00% | 50.00% | ||||||||||||||||||||||
| Stock Issued During Period, Value, Restricted Stock Award, Gross | 80,700 | ||||||||||||||||||||||||
| Proceeds From Issuance Of Common Stock | $ 606,000 | $ 44,240,000 | $ 1,098,000 | ||||||||||||||||||||||