Supplemental disclosures to the consolidated statements of cash flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Net cash provided by operating activities included:
Cash payments for interest	$ 14,755	$ 14,681
Interest capitalized	(2,318)	(3,492)
Cash payments for reorganization items	562	394
Non-cash investing activities included:
Asset retirement obligation additions and revisions	56	76
Financing lease right of use asset additions (see Note 5: Leases)	0	670
Change in accrued oil and gas capital expenditures	$ 6,283	$ 15,174