Mineral Property Transactions	9 Months Ended
Sep. 30, 2012
Mineral Property Transactions [Abstract]
Mineral Property Transactions	3) Mineral Property Transactions Bakken/Three Forks Shale Sale. On January 24, 2012 (but effective December 1, 2011), we sold an undivided 75% of our undeveloped acreage with Zavanna, LLC ("Zavanna") in the Yellowstone and SEHR prospects to GeoResources, Inc. (56.25%) and Yuma Exploration and Production Company, Inc. (18.75%) for $16.7 million and $1.4 million in reimbursed well costs. These amounts were recorded as credits to our full cost pool. In addition we transferred $5.3 million in costs from unevaluated properties to proved properties as a result of this sale. Under the terms of the agreement, we retained the remaining 25% of our interest in the undeveloped acreage and our original working interest in the initial 10 developed wells in the prospects. Our average working interest in the remaining locations will be approximately 8.75% and net revenue interests in new wells after the sale are expected to be in the range of 6.7375% to 7.0%, proportionately reduced depending on Zavanna's actual working interest percentages. Woodbine Acquisition. In May 2012, we entered into a participation agreement with a private entity, Mueller Exploration, Inc. ("Mueller") to participate in the Woodbine Sub-Clarksville 7 Project located in Anderson and Cherokee Counties, Texas. Under the terms of the agreement, we acquired a 26.5% initial working interest (19.6% net revenue interest) in approximately 6,766 gross acres (1,274 net acres to USE) for $1.7 million. The promoted amount covers our portion of the costs for land, geological and geophysical work, as well as all dry hole costs for an initial test well in each of the seven prospects. Upon payout of our initial well costs in each unit, our interest will be reduced to a 19.8% working interest (14.7% net revenue interest). Future infill drilling will be on a heads up basis, and our interest will be a 19.8% working interest (14.7% net revenue interest). Montana Acreage Sale. On June 8, 2012, we sold an undivided 87.5% of our acreage in Daniels County, Montana to a third party for $3.7 million. This amount was recorded as a credit to our full cost pool. In addition we transferred $1.0 million in costs from unevaluated properties to proved properties as a result of this sale. Under the terms of the agreement, we retained a 12.5% working interest in the acreage and reserved overriding royalty interests ("ORRI") in leases we owned that had in excess of 81% NRI. The purchaser also committed to drill a vertical test well to depths sufficient to core the Bakken and Three Forks formations on or before December 31, 2015. We delivered an 80% NRI to the purchaser and a 1% ORRI to a land broker. We also paid the land broker a 10% commission for the cash consideration paid by the purchaser. Bakken/Three Forks Asset Package Acquisition. On September 21, 2012, but effective July 1, 2012, we acquired interests in 27 producing Bakken and Three Forks formation wells and related acreage in McKenzie, Williams and Mountrail Counties of North Dakota for $2.3 million after adjusting for related revenue and operating expenses from the effective date through September 21, 2012. Under the terms of the agreement, we acquired working interests in 23 drilling units ranging from less than 1% to approximately 5%, with an average working interest of 1.45%. All acreage is currently held by production and produces approximately 47 BOE/day net to the Company.

3) Mineral Property Transactions

Bakken/Three Forks Shale Sale. On January 24, 2012 (but effective December 1, 2011), we sold an undivided 75% of our undeveloped acreage with Zavanna, LLC ("Zavanna") in the Yellowstone and SEHR prospects to GeoResources, Inc. (56.25%) and Yuma Exploration and Production Company, Inc. (18.75%) for $16.7 million and $1.4 million in reimbursed well costs. These amounts were recorded as credits to our full cost pool. In addition we transferred $5.3 million in costs from unevaluated properties to proved properties as a result of this sale. Under the terms of the agreement, we retained the remaining 25% of our interest in the undeveloped acreage and our original working interest in the initial 10 developed wells in the prospects. Our average working interest in the remaining locations will be approximately 8.75% and net revenue interests in new wells after the sale are expected to be in the range of 6.7375% to 7.0%, proportionately reduced depending on Zavanna's actual working interest percentages.

Woodbine Acquisition. In May 2012, we entered into a participation agreement with a private entity, Mueller Exploration, Inc. ("Mueller") to participate in the Woodbine Sub-Clarksville 7 Project located in Anderson and Cherokee Counties, Texas. Under the terms of the agreement, we acquired a 26.5% initial working interest (19.6% net revenue interest) in approximately 6,766 gross acres (1,274 net acres to USE) for $1.7 million. The promoted amount covers our portion of the costs for land, geological and geophysical work, as well as all dry hole costs for an initial test well in each of the seven prospects. Upon payout of our initial well costs in each unit, our interest will be reduced to a 19.8% working interest (14.7% net revenue interest). Future infill drilling will be on a heads up basis, and our interest will be a 19.8% working interest (14.7% net revenue interest).

Montana Acreage Sale. On June 8, 2012, we sold an undivided 87.5% of our acreage in Daniels County, Montana to a third party for $3.7 million. This amount was recorded as a credit to our full cost pool. In addition we transferred $1.0 million in costs from unevaluated properties to proved properties as a result of this sale. Under the terms of the agreement, we retained a 12.5% working interest in the acreage and reserved overriding royalty interests ("ORRI") in leases we owned that had in excess of 81% NRI. The purchaser also committed to drill a vertical test well to depths sufficient to core the Bakken and Three Forks formations on or before December 31, 2015. We delivered an 80% NRI to the purchaser and a 1% ORRI to a land broker. We also paid the land broker a 10% commission for the cash consideration paid by the purchaser.

Bakken/Three Forks Asset Package Acquisition. On September 21, 2012, but effective July 1, 2012, we acquired interests in 27 producing Bakken and Three Forks formation wells and related acreage in McKenzie, Williams and Mountrail Counties of North Dakota for $2.3 million after adjusting for related revenue and operating expenses from the effective date through September 21, 2012. Under the terms of the agreement, we acquired working interests in 23 drilling units ranging from less than 1% to approximately 5%, with an average working interest of 1.45%. All acreage is currently held by production and produces approximately 47 BOE/day net to the Company.