Acquisition of additional interests in oil and gas fields.

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Additional acquisitions and divestitures.

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Additional interests acquired through asset exchange.

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Net book value of the disposed assets prior to the sale.

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Combined net production rate of disposed assets (in boepd).

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The Corporation's proportionate interest in oil and gas assets in percentage.

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Gain (loss) from sale or disposal of assets - tax free.

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The difference between the value of the consideration received by the entity and net book value of assets exchanged, after income taxes.

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The difference between the value of the consideration received by the entity and net book value of assets exchanged, before income taxes.

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Net acres acquired.

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Productive capacity of disposed assets (in boepd).

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The total cost of the acquired entity including the cash paid to shareholders of acquired entities, fair value of debt and equity securities issued to shareholders of acquired entities, the fair value of the liabilities assumed, and direct costs of the acquisition.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

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Write-off of the carrying amount of goodwill associated with all or a portion of a reporting unit that is sold in the period.

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-Name Accounting Standards Codification

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The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

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-Name Statement of Financial Accounting Standard (FAS)

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-Glossary Investing Activities

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The difference between the value of the consideration received by the Entity on the sale or disposal and the consideration received by the Entity, including any tax related impact.

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Acquisitions and Divestitures (Details) (USD $) In Millions, unless otherwise specified			1 Months Ended									3 Months Ended
	Sep. 30, 2010 Valhall and Hod fields [Member]	Aug. 31, 2011 Utica Shale play [Member] ac	Feb. 28, 2011 Easington Catchment Area [Member]	Feb. 28, 2011 Bacton Area [Member]	Feb. 28, 2011 Everest Field [Member]	Feb. 28, 2011 Lomond Field [Member]	Aug. 31, 2011 Snorre Field [Member]	Aug. 31, 2011 Cook Field [Member]	Sep. 30, 2010 Valhall Field [Member]	Sep. 30, 2010 Hod Field [Member]	Aug. 31, 2011 United Kingdom North Sea and Norway [Member] boepd	Mar. 31, 2011 United Kingdom North Sea [Member] boepd
Additional Acquisitions and Divestitures (Textual) [Abstract]
The Corporation's proportionate interest in oil and gas assets (in percentages)			30.00%	23.00%	19.00%	17.00%	1.00%	28.00%
Net acres acquired in the Utica Shale Play in Ohio (In acres)		85,000
Business Acquisition, Cost of Acquired Entity, Purchase Price	$ 507	$ 750
Cash received from the sale of oil and gas assets											131	359
Gain on asset sale - before tax												343
Gain on asset exchange before tax	1,150
Gain on asset sale - after tax												310
Gain on asset exchange after tax	1,072
Gain/(Loss) on Asset Sales - Tax Free											103
Carrying value of disposed asset											28	16
Goodwill written off related to sale of business unit											$ 11	$ 14
Acquisition of additional interests in oil and gas fields									8.00%	13.00%
Additional interests acquired through asset exchange									28.00%	25.00%
Combined net production rate of disposed assets (in boepd)											2,500
Productive capacity of disposed assets (in boepd)												15,000