Related parties - Summary (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Related Party Transaction [Line Items]
Capital expenditures for oil and natural gas properties	$ 135,376	$ 152,729
Helmerich & Payne, Inc. \| Affiliated entity
Related Party Transaction [Line Items]
Capital expenditures for oil and natural gas properties	9,151	$ 2,982
Halliburton \| Affiliated entity
Related Party Transaction [Line Items]
Capital expenditures for oil and natural gas properties	$ 27,225

The cash outflow for exploration and development of oil and gas properties. It includes cash payments related to development of oil and gas wells drilled at previously untested geologic structures (to determine the presence of oil or gas) and wells drilled at sites where the presence of oil or gas has already been established (to extract the oil or gas).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585

Name:	us-gaap_PaymentsToExploreAndDevelopOilAndGasProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration