Quarterly report pursuant to Section 13 or 15(d)

Property and Equipment (Narrative) (Details)

v3.5.0.2
Property and Equipment (Narrative) (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Dec. 31, 2015
Property, Plant and Equipment [Line Items]          
Impairment of properties under the full cost method of accounting $ 212,194 $ 594,776 $ 601,806 $ 594,776  
Cumulative capitalization of general and administrative costs incurred and capitalized to the full cost pool 122,800   122,800    
Capitalized general and administrative costs 7,200 $ 7,300 22,200 $ 20,800  
Capitalized costs of oil and natural gas properties excluded from amortization $ 1,723,821   $ 1,723,821   $ 1,817,701
Non-producing leases, extension term     5 years    
Minimum          
Property, Plant and Equipment [Line Items]          
Expected number of years amortization will commence     3 years    
Maximum          
Property, Plant and Equipment [Line Items]          
Expected number of years amortization will commence     5 years