Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Reconciliation of Cash, Cash Equivalents, and Restricted Cash) (Details)

v3.20.1
Summary of Significant Accounting Policies (Reconciliation of Cash, Cash Equivalents, and Restricted Cash) (Details) - USD ($)
$ in Thousands
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Summary Of Significant Accounting Policies [Abstract]        
Cash and cash equivalents $ 45,917 $ 33,360    
Restricted cash - current 911 804    
Restricted cash - non-current 925 920    
Abandonment funding 11,371 11,571    
Total cash, cash equivalents and restricted cash $ 59,124 $ 46,655 $ 32,286 $ 30,643