Annual report pursuant to Section 13 and 15(d)

Loss Per Share (Details)

v3.3.1.900
Loss Per Share (Details) - shares
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Number of common stock warrant and common stock options exercised 25,686,153 5,787,983 10,881,570
Number of common stock issued for stock warrant and stock options exercised 24,466,106 5,392,741 10,732,745
Shares surrendered in lieu of cash payment 1,220,047 426 148,825
Common stock investments, available for sale      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Potential common shares excluded from diluted net loss per share calculation 14,269,717 28,456,149 32,105,859