Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Revenue Recognition (Details)

v3.19.1
Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Accounting Policies [Abstract]    
Revenue $ 0.5 $ 0.4