XML 52 R37.htm IDEA: XBRL DOCUMENT v3.6.0.2
Organization and Significant Accounting Policies (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2016
USD ($)
region
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Nature of operations [Abstract]      
Number of operating regions in domicile country | region 3    
Accounts Receivable [Abstract]      
Allowance for doubtful accounts $ 228 $ 296  
Oil and gas properties, full cost method of accounting:      
Discount rate used in future net cash flows relating to proved oil and gas reserves (in hundredths) 10.00%    
Proved property impairment $ 67,626 128,573 $ 0
Share-Based Payments [Abstract]      
Stock-based compensation expense 3,194 3,912 2,703
Entity's asset retirement obligation transactions [Roll Forward]      
Beginning asset retirement obligation 9,679 9,495  
New wells placed on production and other 119 307  
Deletions related to property disposals and plugging costs (1,832) (793)  
Accretion expense (491) (565) (559)
Revisions 166 105  
Ending asset retirement obligation $ 8,623 $ 9,679 $ 9,495
Revenue Recognition and Major Purchasers [Abstract]      
Entity wide revenue, major customers (in hundredths) 71.00% 54.00% 62.00%
Entity wide revenue, number of major purchasers of oil and gas 2 1 2
Income Taxes [Abstract]      
Valuation allowance for deferred tax assets $ 137,754 $ 103,682 $ 60,086