Quarterly report pursuant to Section 13 or 15(d)

PROPERTY AND EQUIPMENT (Narrative) (Details)

v3.19.2
PROPERTY AND EQUIPMENT (Narrative) (Details)
 3 Months Ended 6 Months Ended
Jun. 30, 2019
USD ($)
Jun. 30, 2018
USD ($)
Jun. 30, 2019
USD ($)
usd_per_mcf
Jun. 30, 2018
USD ($)
usd_per_mcf
Dec. 31, 2018
USD ($)
Property, Plant and Equipment [Line Items]          
Impairment of oil and gas properties $ 0 $ 0 $ 0 $ 0  
Cumulative capitalization of general and administrative costs incurred and capitalized to the full cost pool 219,800,000   219,800,000    
Capitalized general and administrative costs 8,800,000 $ 9,400,000 $ 16,500,000 $ 18,200,000  
Depletion per Mcfe of gas equivalent (usd per Mcfe) | usd_per_mcf     1.00 0.96  
Capitalized costs of oil and natural gas properties excluded from amortization $ 2,836,441,000   $ 2,836,441,000   $ 2,873,037,000
Non-producing leases, extension term 5 years   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