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Divestitures, Assets Held for Sale, and Acquisitions (Tables) | 9 Months Ended
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Sep. 30, 2018
Divestitures, Assets Held for Sale, and Acquisitions [Abstract] |
Disposal Groups, Including Discontinued Operations [Table Text Block] | The following table presents income (loss) before income taxes from the Divide County, North Dakota assets sold for the three and nine months ended September 30, 2018, and 2017. The Divide County Divestiture was considered a disposal of a significant asset group.
| For the Three Months Ended September 30, |  | For the Nine Months Ended September 30,
| 2018 |  | 2017 |  | 2018 |  | 2017
| (in thousands)
Income (loss) before income taxes (1) | $ | — |  |  | $ | 7,593 |  |  | $ | (28,975 | ) |  | $ | (478,572 | )
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(1) | Income (loss) before income taxes reflects oil, gas, and NGL production revenue, less oil, gas, and NGL production expense, depletion, depreciation, amortization, and asset retirement obligation liability accretion expense, impairment expense, and net loss on divestiture activity.

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- Definition Tabular disclosure of information related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 3A -URI http://asc.fasb.org/extlink&oid=109226691&loc=SL51724579-110230 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109222650&loc=d3e1474-107760 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5D -URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721677-107760 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=109222160&loc=SL51721533-107759 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 3A -URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721659-107760 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 4B -URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721665-107760 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2941-110230 Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5C -URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721675-107760 Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760 Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=109222650&loc=d3e1361-107760 Reference 11: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5A -URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721671-107760 Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5B -URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760 Reference 13: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 4A -URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721663-107760 + Details
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