Acquisitions and Divestitures - Additional Information (Details)		1 Months Ended	3 Months Ended		9 Months Ended
	Dec. 19, 2014 USD ($) $ / shares shares	Jun. 30, 2015 USD ($) a Boe Well Location	Sep. 30, 2015 USD ($) a	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) a Location	Sep. 30, 2014 USD ($)	Apr. 30, 2015 USD ($)
Business Acquisition [Line Items]
Proceeds from oil, natural gas and natural gas liquids			$ 13,033,000	$ 11,957,000	$ 39,233,000	$ 35,593,000
Company acquired gross acres | a			1,650		1,650
Working interest acquired					$ 3,300,000
Cash consideration							$ 3,400,000
Gain (loss) on sale of properties			$ (13,000)		$ 1,667,000
Effective date of transaction					Mar. 01, 2015
Legacy Earthstone [Member]
Business Acquisition [Line Items]
Proceeds from oil, natural gas and natural gas liquids			2,000,000		$ 7,300,000
Operating expenses including depletion			2,500,000		8,400,000
Material non-recurring transaction costs			0		0
Earthstone Energy Reverse Acquisition [Member]
Business Acquisition [Line Items]
Common stock shares issued in exchange for acquisition | shares	9,124,000
Common stock, price per share | $ / shares	$ 0.001
2014 Eagle Ford Properties [Member]
Business Acquisition [Line Items]
Percentage of oil and natural gas property interests held by a wholly owned subsidiary	28.57%
Common stock shares issued in exchange for acquisition | shares	2,957,288
Proceeds from oil, natural gas and natural gas liquids			3,200,000		9,800,000
Operating expenses including depletion			2,500,000		7,900,000
Material non-recurring transaction costs			$ 0		$ 0
Acquisition of working interest					33.00%
Number of locations for eagle ford with expected development | Location					16
Consideration paid	$ 56,425,000
Other Acquisitions [Member]
Business Acquisition [Line Items]
Consideration paid		$ 4,066,000
Other Acquisitions [Member] | Austin Chalk Wells [Member]
Business Acquisition [Line Items]
Acquisition of operating interest		50.00%
Company acquired gross acres | a		1,000
Number of wells acquired | Well		2
Percentage of acres held for production		100.00%
Gross production, barrels of oil equivalents per day | Boe		44
Other Acquisitions [Member] | Northern Kames County [Member]
Business Acquisition [Line Items]
Acquisition of working interest		33.00%
Gross acres acquired | a		400
Number of locations for eagle ford with expected development | Location		17
Other Acquisitions [Member] | Banks Field of McKenzie County [Member]
Business Acquisition [Line Items]
Number of wells acquired | Well		41
Consideration paid		$ 1,400,000
Purchase price adjustment for revenues, net for production taxes, operating expenses and capital costs		$ 2,100,000
Net acres acquired | a		164
Number of drilling wells acquired | Well		21