Divestitures, Assets Held for Sale, and Acquisitions	3 Months Ended
Mar. 31, 2019
Divestitures, Assets Held for Sale, and Acquisitions [Abstract]
Divestitures, Assets Held for Sale, and Acquisitions	Note 3 - Divestitures, Assets Held for Sale, and Acquisitions Divestitures On March 26, 2018, the Company divested approximately 112,000 net acres of its Powder River Basin assets (the “PRB Divestiture”) for total cash received at closing, net of costs (referred to throughout this report as “net divestiture proceeds”), of $490.8 million, and recorded an estimated net gain of $409.2 million for the three months ended March 31, 2018. After final purchase price adjustments, the Company received net divestiture proceeds of $492.2 million, and recorded a final net gain of $410.6 million related to these divested assets for the year ended December 31, 2018. During the first quarter of 2018, the company entered into definitive agreements for the sale of its Divide County assets (the “Divide County Divestiture”) and its Halff East assets in the Midland Basin (the “Halff East Divestiture”). Certain of these assets were written down by $24.1 million during the first quarter of 2018 to reflect fair value less estimated costs to sell upon classification as held for sale. These divestitures were completed during the second quarter of 2018. Acquisitions During the first quarter of 2019, the Company completed several non-monetary acreage trades of undeveloped properties located in Howard, Martin, and Midland Counties, Texas, resulting in the exchange of approximately 2,000 net acres, with $65.8 million of carrying value attributed to the properties surrendered by the Company. These trades were recorded at carryover basis with no gain or loss recognized. No such trades occurred during the first quarter of 2018.

Note 3 - Divestitures, Assets Held for Sale, and Acquisitions

Divestitures

On March 26, 2018, the Company divested approximately 112,000 net acres of its Powder River Basin assets (the “PRB Divestiture”) for total cash received at closing, net of costs (referred to throughout this report as “net divestiture proceeds”), of $490.8 million, and recorded an estimated net gain of $409.2 million for the three months ended March 31, 2018. After final purchase price adjustments, the Company received net divestiture proceeds of $492.2 million, and recorded a final net gain of $410.6 million related to these divested assets for the year ended December 31, 2018.

During the first quarter of 2018, the company entered into definitive agreements for the sale of its Divide County assets (the “Divide County Divestiture”) and its Halff East assets in the Midland Basin (the “Halff East Divestiture”). Certain of these assets were written down by $24.1 million during the first quarter of 2018 to reflect fair value less estimated costs to sell upon classification as held for sale. These divestitures were completed during the second quarter of 2018.

Acquisitions

During the first quarter of 2019, the Company completed several non-monetary acreage trades of undeveloped properties located in Howard, Martin, and Midland Counties, Texas, resulting in the exchange of approximately 2,000 net acres, with $65.8 million of carrying value attributed to the properties surrendered by the Company. These trades were recorded at carryover basis with no gain or loss recognized. No such trades occurred during the first quarter of 2018.