Net Income (Loss) Per Common Share - Reconciliation of Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Net income (loss) attributable to Earthstone Energy, Inc.	$ 224	$ 1,556	$ 6,195	$ (14,838)
Net income (loss) per common share attributable to Earthstone Energy, Inc.:
Basic (in dollars per share)	$ 0.01	$ 0.07	$ 0.22	$ (0.66)
Diluted (in dollars per share)	$ 0.01	$ 0.07	$ 0.22	$ (0.66)
Weighted average common shares outstanding
Basic (in shares)	28,257,376	22,905,023	28,011,298	22,638,977
Add potentially dilutive securities:
Unvested restricted stock units (in shares)	54,383	0	97,067	0
Diluted weighted average common shares outstanding (in shares)	28,311,759	22,905,023	28,108,365	22,638,977