Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Property and equipment (Details)

v3.19.2
Summary of Significant Accounting Policies - Property and equipment (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Oil and Gas Properties        
Exploration     $ 0 $ 0
Impairment of oil and gas properties $ 130,999 $ 134,437 212,243 184,973
Impairment of oil and gas properties for leases expired or expected to expire     186,000 $ 185,000
Oil and gas property wells        
Oil and Gas Properties        
Impairment of oil and gas properties     $ 26,000