Properties and Equipment (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Mar. 31, 2020 USD ($)	Sep. 30, 2020 USD ($) Wells	Dec. 31, 2019 USD ($) Wells	Dec. 31, 2018 USD ($)
Property, Plant and Equipment [Line Items]
Document Period End Date		Sep. 30, 2020
Reclassification to Well, Facilities, and Equipment Based on Determination of Proved Reserves	$ (28,011)	$ (20,392)
Proved Natural Gas and Crude Oil Properties		7,389,676	$ 6,241,780
Unproved Natural Gas and Crude Oil Properties		381,428	403,379
Total Natural Gas and Crude Oil Properties		7,771,104	6,645,159
Equipment and other		65,256	41,888
Land and Buildings		24,859	12,312
Construction in Progress		505,930	408,428
Properties and equipment, at cost		8,367,149	7,107,787
Accumulated DD&A		(3,481,915)	(3,012,585)
Property, Plant and Equipment, Net		4,885,234	4,095,202
Capitalized Exploratory Well Cost, Additions Pending Determination of Proved Reserves	31,901	11,540
Capitalized Exploratory Well Costs		$ 7,226	$ 16,078	$ 12,188
Wells to be completed | Wells		2	4
Impairment of properties and equipment	881,100
Delaware Basin Proved Property Impairment	753,000
Delaware Basin Unproved Property Impairment	$ 127,300