Net (Loss) Income Per Common Share - Reconciliation of Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Net (loss) income attributable to Earthstone Energy, Inc.	$ (5,833)	$ 16,708
Net (loss) income per common share attributable to Earthstone Energy, Inc.:
Basic (in dollars per share)	$ (0.14)	$ 0.57
Diluted (in dollars per share)	$ (0.14)	$ 0.57
Weighted average common shares outstanding
Basic (in shares)	42,778,916	29,497,428
Add potentially dilutive securities:
Unvested restricted stock units (in shares)	0	0
Unvested performance units (in shares)	0	0
Diluted weighted average common shares outstanding (in shares)	42,778,916	29,497,428