Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Restricted Cash (Details)

v3.10.0.1
Summary of Significant Accounting Policies - Restricted Cash (Details) - USD ($)
$ in Thousands
Sep. 30, 2018
Dec. 31, 2017
Sep. 30, 2017
Accounting Policies [Abstract]      
Restricted cash non-current $ 19,025 $ 20,092 $ 19,397