Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation (Details)

v3.10.0.1
Basis of Presentation (Details) - USD ($)
$ in Thousands
Sep. 30, 2018
Dec. 31, 2017
Sep. 30, 2017
Dec. 31, 2016
Current Assets:        
Cash and cash equivalents $ 153,542 $ 60,115    
Restricted cash included in prepaid expenses and other current assets 158 2,000    
Total cash, cash equivalents and restricted cash $ 153,700 $ 62,115 $ 50,704 $ 54,592