Supplemental disclosures to the consolidated statements of cash flows (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Net cash provided by operating activities included:
Cash payments for interest	$ 16,942	$ 16,328
Interest capitalized	(3,900)	(6,613)
Cash payments for reorganization items	1,189	857
Non-cash investing activities included:
Asset retirement obligation additions and revisions	133	386
Financing lease right of use asset additions (see Note 5: Leases)	0	1,387
Change in accrued oil and gas capital expenditures	$ (22,418)	$ 7,024