Annual report pursuant to Section 13 and 15(d)

Net Income (Loss) per Share Available to Common Stockholders - Outstanding Securities Considered Anti-Dilutive (Details)

v3.8.0.1
Net Income (Loss) per Share Available to Common Stockholders - Outstanding Securities Considered Anti-Dilutive (Details) - shares
shares in Thousands
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]      
Antidilutive securities excluded from computation of earnings per share (in shares) 4,818 1,442 1,510
Common Stock Options and RSUs [Member]      
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]      
Antidilutive securities excluded from computation of earnings per share (in shares) 346 548 550
Warrants for Common Stock [Member]      
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]      
Antidilutive securities excluded from computation of earnings per share (in shares) 100 894 960
Convertible Preferred Stock [Member]      
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]      
Antidilutive securities excluded from computation of earnings per share (in shares) 4,372