CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares
6 Months Ended 12 Months Ended
Jun. 30, 2015
Dec. 31, 2014
Common stock, par value per share (in dollars per share) $ 0.000666 $ 0.000666
Common stock, shares authorized 3,950,000,000 3,950,000,000
Common stock, shares issued 85,173,255 82,480,600
Common stock, shares outstanding 85,173,255 82,480,600
Preferred stock, shares authorized 50,000,000 50,000,000
7.5% Series A-1 Convertible Preferred Stock [Member]    
Preferred stock, dividend rate 7.50% 7.50%
Preferred stock, par or stated value per share (in dollars per share) $ 0.000666 $ 0.000666
Preferred stock, shares authorized 1,500,000 1,500,000
Preferred stock, shares issued 24,362 24,362
Preferred stock, shares outstanding 24,362 24,362
7.5% Series A-2 Convertible Preferred Stock [Member]    
Preferred stock, dividend rate 7.50% 7.50%
Preferred stock, par or stated value per share (in dollars per share) $ 0.000666 $ 0.000666
Preferred stock, shares authorized 250,000 250,000
Preferred stock, shares issued 1,610 1,610
Preferred stock, shares outstanding 1,610 1,610
7.5% Series B Convertible Preferred Stock    
Preferred stock, dividend rate 7.50% 7.50%
Preferred stock, par or stated value per share (in dollars per share) $ 0.000666 $ 0.000666
Preferred stock, shares authorized 600,000 600,000
Preferred stock, shares issued 22,626 22,676
Preferred stock, shares outstanding 22,626 22,676