Quarterly report pursuant to Section 13 or 15(d)

New Accounting Standards (Reconciliation Of Cash, Cash Equivalents, And Restricted Cash) (Details)

v3.8.0.1
New Accounting Standards (Reconciliation Of Cash, Cash Equivalents, And Restricted Cash) (Details) - USD ($)
$ in Thousands
Mar. 31, 2018
Dec. 31, 2017
Mar. 31, 2017
Dec. 31, 2016
New Accounting Standards [Abstract]        
Cash and cash equivalents $ 32,205 $ 19,669    
Restricted cash - current 866 842    
Restricted cash - non-current 968 967    
Abandonment funding 10,808 10,808    
Total cash, cash equivalents and restricted cash shown in the condensed consolidated statement of cash flows $ 44,847 $ 32,286 $ 34,428 $ 30,643