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Suspended Exploratory Well Costs (Tables) | 12 Months Ended
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Dec. 31, 2017
SUSPENDED EXPLORATORY WELL COSTS |
Schedule of capitalized well cost rollforward |
($ millions) |  | 2017 |  | 2016 |  |
Beginning of year |  | — |  | 212 |  |
Additions |  | — |  | 209 |  |
Transfers to oil and gas assets |  | — |  | (65 | ) |
Capitalized exploratory well costs charged to expense |  | — |  | (356 | ) |
End of year |  | — |  | — |  |

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- Definition Tabular disclosure of the change in capitalized exploratory costs during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 932 -SubTopic 235 -Section 50 -Paragraph 1B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=68064819&loc=SL6806780-109447 + Details
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