Stockholders' Equity (Details) $ / shares in Units, $ in Thousands | May. 05, 2015USD ($)$ / sharesshares | Apr. 30, 2015USD ($)shares | Oct. 31, 2014$ / sharesshares | Sep. 30, 2014USD ($)WarrantHolder$ / sharesshares | Jun. 30, 2015USD ($)$ / sharesshares | Dec. 31, 2014USD ($)$ / sharesshares | Sep. 10, 2014$ / shares | Jun. 04, 2014$ / shares | May. 31, 2014$ / shares |
Preferred Stock [Abstract] | | | | | | | | | |
Preferred stock, shares authorized (in shares) | | | | | 5,000,000 | | | | |
Preferred stock, par value (in dollars per share) | $ / shares | | | | | $ 0.001 | | | | |
Common Stock [Abstract] | | | | | | | | | |
Period exercisable from the date of issuance | | | 6 months | 6 months 1 day | | | | | |
Number of warrant holders | WarrantHolder | | | | 13 | | | | | |
Number of shares called by warrants (in shares) | | | | 4,000,000 | | | | | |
Common stock, par value (in dollars per share) | $ / shares | | | | | $ 0.001 | $ 0.001 | | | |
Warrant exercise price (in dollars per share) | $ / shares | | | | $ 2 | | | $ 1 | $ 3 | |
Period in which warrants will expire | | | | 5 years | | | | | |
Warrants with reduced exercise price (in shares) | | | 3,400,000 | | | | | | |
Conversion price (in dollars per share) | $ / shares | | | $ 0.52 | | | | | | |
Percentage of shares equal to purchase of warrants (in hundredths) | | | 100.00% | | | | | | |
Proceeds from exercise of warrants | $ | | | | $ 4,000 | | | | | |
Warrants [Member] | | | | | | | | | |
Common Stock [Abstract] | | | | | | | | | |
Warrants exercised (in shares) | | | | | 3,400,000 | | | | |
October 2014 Warrants [Member] | | | | | | | | | |
Common Stock [Abstract] | | | | | | | | | |
Common stock at purchase price (in dollars per unit) | $ / shares | | | | | $ 0.56 | 0.49 | | | |
Period exercisable from the date of issuance | | | | | 6 months | | | | |
Warrant exercise price (in dollars per share) | $ / shares | | | | | $ 0.5771 | | | | |
Proceeds from exercise of warrants | $ | | | | | $ 4,900 | | | | |
Warrants exercised (in shares) | | | | | 8,500,000 | | | | |
Number of warrants outstanding (in shares) | | | | | 17,500,000 | | | | |
May 2015 Warrants [Member] | | | | | | | | | |
Common Stock [Abstract] | | | | | | | | | |
Common stock at purchase price (in dollars per unit) | $ / shares | | | | | $ 0.56 | $ 0 | | | |
Period exercisable from the date of issuance | 6 months 1 day | | | | 6 months 1 day | | | | |
Warrant exercise price (in dollars per share) | $ / shares | $ 1.02 | | | | $ 1.02 | | | | |
Period in which warrants will expire | 5 years | | | | | | | | |
Number of common stock and warrant available in each unit of subscription agreement (in shares) | 1 | | | | | | | | |
Common stock issued, value | $ | | | | | $ 25,000 | | | | |
Each unit consist of number of common stock and warrant (in shares) | 1 | | | | | | | | |
Institutional Investors [Member] | | | | | | | | | |
Common Stock [Abstract] | | | | | | | | | |
Common stock issued (in shares) | | | 13,500 | | | | | | |
Sale of stock, price per share (in dollars per share) | $ / shares | | | $ 1,000 | | | | | | |
Period in which warrants will expire | | | 5 years | | | | | | |
Number of common stock and warrant available in each unit of subscription agreement (in shares) | 1 | | 1 | | | | | | |
Common stock issued, value | $ | $ 25,000 | | | | | | | | |
Each unit consist of number of common stock and warrant (in shares) | 1 | | 1 | | | | | | |
Institutional Investors [Member] | May 2015 Warrants [Member] | | | | | | | | | |
Common Stock [Abstract] | | | | | | | | | |
Proceeds from private placement of stock | $ | $ 17,700 | | | | | | | | |
Common stock at purchase price (in dollars per unit) | $ / shares | $ 0.77 | | | | | | | | |
Number of common stock and warrant available in each unit of subscription agreement (in shares) | 1 | | | | | | | | |
Common stock issued, value | $ | $ 25,000 | | | | | | | | |
Each unit consist of number of common stock and warrant (in shares) | 1 | | | | | | | | |
Cowen and Company, LLC [Member] | | | | | | | | | |
Common Stock [Abstract] | | | | | | | | | |
Proceeds from private placement of stock | $ | | $ 7,200 | | | | | | | |
Common stock issued (in shares) | | 5,800,000 | | | | | | | |
Common stock, par value (in dollars per share) | $ / shares | | | | | | | | | $ 0.001 |
Series A Preferred Stock [Member] | | | | | | | | | |
Preferred Stock [Abstract] | | | | | | | | | |
Preferred stock, shares authorized (in shares) | | | | | 5,000,000 | 5,000,000 | | | |
Preferred stock, par value (in dollars per share) | $ / shares | | | | | $ 0.001 | $ 0.001 | | | |
Preferred stock, shares outstanding (in shares) | | | | | 0 | 5,311 | | | |
Preferred stock, shares issued (in shares) | | | | | 13,500 | 13,500 | | | |
Convertible preferred stock (in hundredths) | | | | | 3.60% | 3.60% | | | |
Common Stock [Abstract] | | | | | | | | | |
Cashless exercise of warrants | $ | | | | | $ 1,800 | | | | |
Proceeds from exercise of warrants | $ | | | | | 100 | | | | |
Series A Preferred Stock [Member] | Dividend Declared [Member] | | | | | | | | | |
Common Stock [Abstract] | | | | | | | | | |
Dividends Payable | $ | | | | | | $ 70 | | | |
Series A Preferred Stock [Member] | Dividend Paid [Member] | | | | | | | | | |
Common Stock [Abstract] | | | | | | | | | |
Dividends Payable | $ | | | | | $ 700 | $ 1,200 | | | |
Warrants [Member] | | | | | | | | | |
Common Stock [Abstract] | | | | | | | | | |
Warrant exercise price (in dollars per share) | $ / shares | | | $ 0.5771 | | | | | | |