Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies (Restricted Cash) (Details)

v3.19.2
Summary of Significant Accounting Policies (Restricted Cash) (Details) - USD ($)
$ in Thousands
Jun. 30, 2019
Dec. 31, 2018
Jun. 30, 2018
Dec. 31, 2017
Accounting Policies [Abstract]        
Cash and cash equivalents $ 61,597 $ 123,575 $ 221,775  
Restricted cash 3,000 3,000 0  
Total cash, cash equivalents and restricted cash in the Condensed Statements of Cash Flows $ 64,597 $ 126,575 $ 221,775 $ 77,627