Acquisitions and Divestitures - Pro Forma (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Business Combination and Asset Acquisition [Abstract]
Revenue	$ 460,948	$ 287,359
Income (loss) before taxes	88,917	(239,752)
Net income (loss)	87,058	(239,980)
Less: Net income (loss) attributable to noncontrolling interest	36,833	(99,695)
Net income (loss) attributable to Earthstone Energy, Inc.	$ 50,226	$ (140,285)
Basic (in dollars per share)	$ 1.06	$ (2.87)
Diluted (in dollars per share)	$ 1.01	$ (2.87)