Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Recently Adopted Accounting Pronouncements (Details)

v3.8.0.1
Summary of Significant Accounting Policies - Recently Adopted Accounting Pronouncements (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Recently Adopted Accounting Pronouncements    
Revenue $ 0.4  
Restricted cash, security deposit 0.5 $ 0.5
ASU 2014-09 | Before topic 606    
Recently Adopted Accounting Pronouncements    
Revenue 0.4  
ASU 2016-18    
Recently Adopted Accounting Pronouncements    
Restricted cash, security deposit $ 0.5