Property and Equipment (Narrative) (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | |||
---|---|---|---|---|---|
Jun. 30, 2017 |
Jun. 30, 2016 |
Jun. 30, 2017 |
Jun. 30, 2016 |
Dec. 31, 2016 |
|
Property, Plant and Equipment [Line Items] | |||||
Impairment of oil and natural gas properties | $ 0 | $ 170,621 | $ 0 | $ 389,612 | |
Cumulative capitalization of general and administrative costs incurred and capitalized to the full cost pool | 146,600 | 146,600 | |||
Capitalized general and administrative costs | 8,300 | $ 7,900 | 16,700 | $ 15,000 | |
Capitalized costs of oil and natural gas properties excluded from amortization | $ 3,109,143 | $ 3,109,143 | $ 1,580,305 | ||
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 |