Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Revenue Recognition (Details)

v3.10.0.1
Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Accounting Policies [Abstract]      
Operating lease revenue $ 7,238 $ 3,409 $ 3,162