Subsequent Events	9 Months Ended
Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On October 8, 2018, the Company announced the closing of an acreage trade with an undisclosed operator in the Midland Basin of Texas. Under the terms of the acreage trade, the Company acquired 3,899 net operated acres in Reagan County with virtually a 100% working interest, in exchange for 1,222 net non-operated acres in Glasscock County with an average working interest of 39% and $27.8 million in cash, plus customary closing adjustments. On October 17, 2018, Earthstone, EEH and Sabalo Holdings, LLC (“Sabalo Holdings”) entered into an agreement (the “Sabalo Contribution Agreement”) which provides for the contribution by Sabalo Holdings of all its interests in Sabalo Energy, LLC (“Sabalo Energy”) and Sabalo Energy, Inc. to EEH. Also, on October 17, 2018, Sabalo Energy entered into a letter agreement (the “Shad Letter Agreement”) to acquire certain wellbore interests and related equipment held by Shad Permian, LLC (“Shad”) that are part of a joint venture between Sabalo Energy and Shad involving certain acreage covered by the Sabalo Contribution Agreement. Under those agreements, EEH expects to acquire (the “Acquisition”) an aggregate of approximately 20,800 net acres located in the Midland Basin of Texas with approximately 488 gross operated and 349 gross non-operated horizontal drilling locations with approximately 125 gross (67.4 net) existing vertical and horizontal wells on the acreage (and associated equipment and gathering infrastructure) for an aggregate purchase price of approximately $950 million, subject to certain purchase price and post-closing adjustments as set forth in the Sabalo Contribution Agreement and the Shad Letter Agreement. The aggregate purchase price of approximately $950 million for the Acquisition will include: (i) approximately $650 million in cash, which the Company intends to partially fund from (a) the net proceeds from the sale of Preferred Stock (as described below); (b) an unsecured bridge loan and/or an unsecured note offering (as described below); and (c) borrowings under an amended and restated five-year senior secured reserve-based revolving credit facility at EEH (the “New Credit Facility”); and (ii) approximately $300 million in equity comprised of the issuance of 32,315,695 EEH Units and 32,315,695 shares of Class B Common Stock. Upon the terms and conditions in the Sabalo Contribution Agreement, concurrently with closing of the Acquisition, EEH will amend its limited liability company agreement to admit Sabalo Holdings as a member. Each EEH Unit, together with a corresponding share of Class B Common Stock will be exchangeable, at the option of the holder any time after the closing of the Acquisition, for one share of Class A Common Stock. On October 17, 2018, Earthstone and EIG ESTE Equity Aggregator, L.P. (“EIG”) entered into a Securities Purchase Agreement (the “Purchase Agreement”) relating to the sale by Earthstone and the purchase by EIG of $225 million of the Series A Redeemable Convertible Preferred Stock, $0.001 par value per share of Earthstone (the “Preferred Stock”), to be authorized by Earthstone, and up to $30 million of Class A Common Stock. The closing of the Purchase Agreement is expected to occur simultaneously with the closing of the Sabalo Contribution Agreement. On October 17, 2018, EEH entered into a commitment letter (the “Commitment Letter”) with Wells Fargo Bank, National Association (“Wells Fargo Bank”), Royal Bank of Canada (“Royal Bank”), SunTrust Bank (“SunTrust”), BOKF, NA (“BOKF”) and PNC Bank National Association (“PNC Bank”) (collectively, the “Banks”) pursuant to which the Banks committed on a several, not joint, basis to provide, subject to customary closing conditions, New Credit Facility to the Company with a minimum initial borrowing base of $475 million. Borrowings under the facility may be used to pay part of the cash portion of the purchase price under the Sabalo Contribution Agreement, to refinance certain existing indebtedness of the Company and its subsidiaries and to pay fees and expenses in connection with the foregoing. Further, Wells Fargo Bank, Royal Bank, SunTrust and Jefferies Finance LLC, severally and not jointly, committed to provide the Company with a senior unsecured term loan bridge facility (“Bridge Facility”) of up to $500 million. The Bridge Facility will mature on the date that is twelve months after the closing date of the Sabalo Contribution Agreement and, if not repaid in full on such date and subject to the satisfaction of conditions set forth in the Commitment Letter, will automatically be converted into an extended term loan facility that will mature on the eighth anniversary of the closing date of the Sabalo Contribution Agreement. The Bridge Facility may be used to close the Sabalo Contribution Agreement if a contemplated private sale of approximately $500 million of senior unsecured notes has not been completed at that time. Proceeds from the sale of such unsecured notes are expected to repay any amounts drawn down under the Bridge Facility. On November 2, 2018, the Company received commitments from a syndicate of banks, including the Banks, for an increased minimum initial borrowing base of $550 million for the New Credit Facility. On November 6, 2018, lenders under the EEH Credit Agreement increased the borrowing base from $225 million to $275 million.

Subsequent Events

On October 8, 2018, the Company announced the closing of an acreage trade with an undisclosed operator in the Midland Basin of Texas. Under the terms of the acreage trade, the Company acquired 3,899 net operated acres in Reagan County with virtually a 100% working interest, in exchange for 1,222 net non-operated acres in Glasscock County with an average working interest of 39% and $27.8 million in cash, plus customary closing adjustments.

On October 17, 2018, Earthstone, EEH and Sabalo Holdings, LLC (“Sabalo Holdings”) entered into an agreement (the “Sabalo Contribution Agreement”) which provides for the contribution by Sabalo Holdings of all its interests in Sabalo Energy, LLC (“Sabalo Energy”) and Sabalo Energy, Inc. to EEH. Also, on October 17, 2018, Sabalo Energy entered into a letter agreement (the “Shad Letter Agreement”) to acquire certain wellbore interests and related equipment held by Shad Permian, LLC (“Shad”) that are part of a joint venture between Sabalo Energy and Shad involving certain acreage covered by the Sabalo Contribution Agreement. Under those agreements, EEH expects to acquire (the “Acquisition”) an aggregate of approximately 20,800 net acres located in the Midland Basin of Texas with approximately 488 gross operated and 349 gross non-operated horizontal drilling locations with approximately 125 gross (67.4 net) existing vertical and horizontal wells on the acreage (and associated equipment and gathering infrastructure) for an aggregate purchase price of approximately $950 million, subject to certain purchase price and post-closing adjustments as set forth in the Sabalo Contribution Agreement and the Shad Letter Agreement.

The aggregate purchase price of approximately $950 million for the Acquisition will include: (i) approximately $650 million in cash, which the Company intends to partially fund from (a) the net proceeds from the sale of Preferred Stock (as described below); (b) an unsecured bridge loan and/or an unsecured note offering (as described below); and (c) borrowings under an amended and restated five-year senior secured reserve-based revolving credit facility at EEH (the “New Credit Facility”); and (ii) approximately $300 million in equity comprised of the issuance of 32,315,695 EEH Units and 32,315,695 shares of Class B Common Stock. Upon the terms and conditions in the Sabalo Contribution Agreement, concurrently with closing of the Acquisition, EEH will amend its limited liability company agreement to admit Sabalo Holdings as a member. Each EEH Unit, together with a corresponding share of Class B Common Stock will be exchangeable, at the option of the holder any time after the closing of the Acquisition, for one share of Class A Common Stock.

On October 17, 2018, Earthstone and EIG ESTE Equity Aggregator, L.P. (“EIG”) entered into a Securities Purchase Agreement (the “Purchase Agreement”) relating to the sale by Earthstone and the purchase by EIG of $225 million of the Series A Redeemable Convertible Preferred Stock, $0.001 par value per share of Earthstone (the “Preferred Stock”), to be authorized by Earthstone, and up to $30 million of Class A Common Stock. The closing of the Purchase Agreement is expected to occur simultaneously with the closing of the Sabalo Contribution Agreement.

On October 17, 2018, EEH entered into a commitment letter (the “Commitment Letter”) with Wells Fargo Bank, National Association (“Wells Fargo Bank”), Royal Bank of Canada (“Royal Bank”), SunTrust Bank (“SunTrust”), BOKF, NA (“BOKF”) and PNC Bank National Association (“PNC Bank”) (collectively, the “Banks”) pursuant to which the Banks committed on a several, not joint, basis to provide, subject to customary closing conditions, New Credit Facility to the Company with a minimum initial borrowing base of $475 million. Borrowings under the facility may be used to pay part of the cash portion of the purchase price under the Sabalo Contribution Agreement, to refinance certain existing indebtedness of the Company and its subsidiaries and to pay fees and expenses in connection with the foregoing.

Further, Wells Fargo Bank, Royal Bank, SunTrust and Jefferies Finance LLC, severally and not jointly, committed to provide the Company with a senior unsecured term loan bridge facility (“Bridge Facility”) of up to $500 million. The Bridge Facility will mature on the date that is twelve months after the closing date of the Sabalo Contribution Agreement and, if not repaid in full on such date and subject to the satisfaction of conditions set forth in the Commitment Letter, will automatically be converted into an extended term loan facility that will mature on the eighth anniversary of the closing date of the Sabalo Contribution Agreement. The Bridge Facility may be used to close the Sabalo Contribution Agreement if a contemplated private sale of approximately $500 million of senior unsecured notes has not been completed at that time. Proceeds from the sale of such unsecured notes are expected to repay any amounts drawn down under the Bridge Facility.

On November 2, 2018, the Company received commitments from a syndicate of banks, including the Banks, for an increased minimum initial borrowing base of $550 million for the New Credit Facility.

On November 6, 2018, lenders under the EEH Credit Agreement increased the borrowing base from $225 million to $275 million.