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- Definition

The aggregate of amounts due from customers or clients, within one year of the balance sheet date (or one operating cycle, if longer), for goods or services that have been delivered or sold in the normal course of business and an amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date within one year of the balance sheet, reduced to their estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection and net of any write-downs taken for collection uncertainty on the part of the holder, respectively.

+ References

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- Definition

Amount classified as assets attributable to disposal group held for sale or disposed of.

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- Definition

Amount before tax of gain (loss) recognized on the sale or disposal of a disposal group. Excludes discontinued operations.

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- Definition

The expense recorded to reduce the value of oil and gas assets consisting of proved properties and unproved properties as the estimate of future successful production from these properties is reduced.

+ References

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

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount classified as liabilities attributable to disposal group held for sale or disposed of.

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- Definition

The cash inflow to dispose of long-lived, physical assets and mineral interests in oil and gas properties used for normal oil and gas operations.

+ References

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

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

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Dispositions (Details)		1 Months Ended				2 Months Ended	3 Months Ended					9 Months Ended
Dispositions (Details)	May 31, 2017 USD ($)	Oct. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Nov. 30, 2016 USD ($)	Oct. 31, 2016 USD ($)	Apr. 30, 2016 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Oil and Gas Property and Equipment												$ 1,757,000,000	$ 837,000,000
Impairments							$ 201,000,000				$ 47,000,000	205,000,000	48,000,000
Oil Sands Mining Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal							0				0	(43,000,000)	0
Impairments							0		$ 6,600,000,000		0	6,636,000,000	$ 0
Discontinued Operations, Disposed of by Sale [Member] \| Oil Sands Mining Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Oil and Gas Property and Equipment	$ 1,800,000,000						2,500,000,000
Number of notes receivable	2
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal								$ (43,000,000)
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| Oklahoma Resource Basin [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Oil and Gas Property and Equipment			$ 25,000,000
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal			21,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| West Texas and New Mexico [Domain]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Oil and Gas Property and Equipment					$ 235,000,000						67,000,000
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal					$ 63,000,000						55,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| Wyoming Upstream and Midstream Assets Sold [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Oil and Gas Property and Equipment				$ 155,000,000							690,000,000
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal										$ 38,000,000	$ 266,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| Shenandoah in Gulf of Mexico, Piceance in Colorado, and West Texas [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Oil and Gas Property and Equipment						$ 80,000,000
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal								$ (48,000,000)
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| Non-core [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from Sale of Oil and Gas Property and Equipment							53,000,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] \| Non-core [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets			63,000,000				63,000,000					63,000,000
Disposal Group, Including Discontinued Operation, Liabilities			$ 2,000,000				$ 2,000,000					$ 2,000,000
Oil Sands Mining Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairments									$ 4,960,000,000
Variable Interest Entity, Not Primary Beneficiary [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage												20.00%
Variable Interest Entity, Not Primary Beneficiary [Member] \| Oil Sands Mining Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage												20.00%
Note Receivable 2 [Member] \| Discontinued Operations, Disposed of by Sale [Member] \| Oil Sands Mining Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accounts, Notes, Loans and Financing Receivable, Net, Current	$ 375,000,000
Note Receivable 1 [Member] \| Discontinued Operations, Disposed of by Sale [Member] \| Oil Sands Mining Segment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accounts, Notes, Loans and Financing Receivable, Net, Current	$ 375,000,000
Subsequent Event [Member] \| Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] \| Shenandoah in Gulf of Mexico, Piceance in Colorado, and West Texas [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal		$ 30,000,000