Additional term of FPSO capital lease.

No definition available.

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- Definition

Initial term of FPSO capital lease.

+ References

No definition available.

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Balance Type:	na
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- Definition

Minimum reference rate to compute the variable rate on a debt instrument.

+ References

No definition available.

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Period Type:	duration

- Definition

The amount to which the maximum borrowing capacity under the credit facility could be expanded without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

No definition available.

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- Definition

Non-operating leasehold interest ownership percentage.

+ References

No definition available.

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- Definition

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

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- Definition

Amount before accumulated depreciation of leased physical assets used in the normal conduct of business to produce goods and services.

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- Definition

Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

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- Definition

Earliest date before maturity when the issuer can call the outstanding debt instrument for repayment or conversion to equity, in CCYY-MM-DD format.

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- Definition

Face (par) amount of debt instrument at time of issuance.

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- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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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

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

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- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

Gross amount of debt extinguished.

+ References

No definition available.

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- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

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Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate at the end of the reporting period.

+ References

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

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Balance Type:	credit
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- Definition

Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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- Definition

The cash outflow for incremental, external costs directly pertaining to an early extinguishment of debt, including legal costs and prepayment penalties, and excluding interest and repayment of debt principal.

+ References

No definition available.

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Debt and Interest Expense - Additional Information (Detail) - USD ($)		3 Months Ended		9 Months Ended
	Oct. 18, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Debt Instrument [Line Items]
Debt instrument, principal amount		$ 17,285,000,000		$ 17,285,000,000		$ 17,312,000,000
Loss on early extinguishment of debt		0	$ 0	124,000,000	$ 0
Premiums for early retirement and redemption of senior notes				114,000,000
FPSO capital lease obligation		245,000,000		245,000,000		20,000,000
Five-Year Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit, maximum capacity		3,000,000,000		$ 3,000,000,000
Debt instrument, term				5 years
Line of credit, expiration date				Jan. 23, 2021
Line of credit, outstanding borrowings		0		$ 0
364-Day Credit Facility Due 2017 [Member]
Debt Instrument [Line Items]
Line of credit, maximum capacity		2,000,000,000		$ 2,000,000,000
Debt instrument, term				364 days
Line of credit, expiration date				Jan. 15, 2017
Line of credit, outstanding borrowings		0		$ 0
Commercial Paper [Member]
Debt Instrument [Line Items]
Line of credit, maximum capacity		3,000,000,000		3,000,000,000
Commercial paper, outstanding borrowings		0		$ 0
Commercial Paper [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, term				397 days
WES RCF [Member]
Debt Instrument [Line Items]
Line of credit, maximum capacity		1,200,000,000		$ 1,200,000,000
Debt instrument, term				5 years
Line of credit, expiration date				Feb. 26, 2019
Line of credit, outstanding borrowings		$ 20,000,000		$ 20,000,000
Line of credit, interest rate		1.82%		1.82%
Line of credit, available borrowing capacity		$ 1,180,000,000		$ 1,180,000,000
Line of credit, expandable maximum capacity		1,500,000,000		1,500,000,000
Letters of credit, outstanding		5,000,000		5,000,000
WGP RCF [Member]
Debt Instrument [Line Items]
Line of credit, maximum capacity		250,000,000		$ 250,000,000
Debt instrument, term				3 years
Line of credit, expiration date				Mar. 14, 2019
Line of credit, outstanding borrowings		$ 28,000,000		$ 28,000,000
Line of credit, interest rate		2.53%		2.53%
Line of credit, available borrowing capacity		$ 222,000,000		$ 222,000,000
Line of credit, expandable maximum capacity		500,000,000		$ 500,000,000
WGP RCF [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Line of credit, variable rate floor				0.00%
WGP RCF [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| Alternate Base Rate [Member]
Debt Instrument [Line Items]
Applicable margin added				1.00%
WGP RCF [Member] \| Percentage Above Federal Funds Effective Rate [Member] \| Alternate Base Rate [Member]
Debt Instrument [Line Items]
Applicable margin added				0.50%
WGP RCF [Member] \| Minimum [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Applicable margin added				2.00%
WGP RCF [Member] \| Minimum [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Applicable margin added				1.00%
WGP RCF [Member] \| Maximum [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Applicable margin added				2.75%
WGP RCF [Member] \| Maximum [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Applicable margin added				1.75%
Fair Value, Inputs, Level 2 [Member] \| Market Approach Valuation Technique [Member]
Debt Instrument [Line Items]
Estimated fair value of total borrowings		17,600,000,000		$ 17,600,000,000		$ 15,700,000,000
Senior Notes 1 Through 3 [Member]
Debt Instrument [Line Items]
Debt instrument, principal amount		3,000,000,000		3,000,000,000
Portion of 6.375% Senior Notes Due 2017 [Member]
Debt Instrument [Line Items]
Amount of debt extinguished				1,250,000,000
6.375% Senior Notes Due 2017 [Member]
Debt Instrument [Line Items]
Debt instrument, principal amount		$ 2,000,000,000		$ 2,000,000,000
Debt instrument, stated interest rate		6.375%		6.375%
Debt instrument, maturity date				Sep. 15, 2017
5.950% Senior Notes Due 2016 [Member]
Debt Instrument [Line Items]
Amount of debt extinguished				$ 1,750,000,000
Debt instrument, stated interest rate		5.95%		5.95%
Debt instrument, maturity date				Sep. 15, 2016
Zero-Coupon Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date				Oct. 10, 2036
Debt Instrument, earliest call date				Oct. 10, 2016
Zero-Coupon Senior Notes [Member] \| Accreted Value at Next Potential Put Date [Member]
Debt Instrument [Line Items]
Debt instrument, accreted value		$ 839,000,000		$ 839,000,000
WES 4.650% Senior Notes Due 2026 [Member]
Debt Instrument [Line Items]
Debt instrument, principal amount		$ 500,000,000		$ 500,000,000
Debt instrument, stated interest rate		4.65%		4.65%
Debt instrument, maturity date				Jul. 15, 2026
WES 5.450% Senior Notes Due 2044 \| Subsequent Event [Member]
Debt Instrument [Line Items]
Debt instrument, principal amount	$ 200,000,000
Debt instrument, stated interest rate	5.45%
Debt instrument, maturity date	Apr. 01, 2044
FPSO Capital Lease [Member]
Debt Instrument [Line Items]
FPSO nonoperated working interest		19.00%		19.00%
FPSO capital lease asset		$ 225,000,000		$ 225,000,000
FPSO capital lease obligation		$ 225,000,000		$ 225,000,000
FPSO capital lease initial term				10 years
FPSO capital lease additional term				10 years