Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2020
Accounting Policies [Abstract]
Consolidation Principles and Investments	Consolidation Principles and Investments —Our consolidated financial statements include the accounts of majority-owned, controlled subsidiaries and variable interest entities where we are the primary beneficiary. The equity method is used to account for investments in affiliates in which we have the ability to exert significant influence over the affiliates’ operating and financial policies. When we do not have the ability to exert significant influence, the investment is measured at fair value except when the investment does not have a readily determinable fair value. For those exceptions, it will be measured at cost minus impairment, plus or minus observable price changes in orderly transactions for an identical or similar investment of the same issuer. Undivided interests in oil and gas joint ventures, pipelines, natural gas plants and terminals are consolidated on a proportionate basis. Other securities and investments are generally carried at cost. We manage our operations through six operating segments, defined by geographic region: Alaska; Lower 48; Canada; Europe, Middle East and North Africa; Asia Pacific; and Other International. For additional information, see Note 24—Segment Disclosures and Related Information. The unrealized (gain) loss on investment in Cenovus Energy included on our consolidated statement of cash flows, previously reflected on the line item “Other” within net cash provided by operating activities, has been reclassified in the comparative periods to conform with the current period’s presentation.
Foreign Currency Translation	Foreign Currency Translation —Adjustments resulting from the process of translating foreign functional currency financial statements into U.S. dollars are included in accumulated other comprehensive loss in common stockholders’ equity. Foreign currency transaction gains and losses are included in current earnings. Some of our foreign operations use their local currency as the functional currency.
Use of Estimates	Use of Estimates —The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosures of contingent assets and liabilities. Actual results could differ from these estimates.
Revenue Recognition	Revenue Recognition —Revenues associated with the sales of crude oil, bitumen, natural gas, LNG, NGLs and other items are recognized at the point in time when the customer obtains control of the asset. In evaluating when a customer has control of the asset, we primarily consider whether the transfer of legal title and physical delivery has occurred, whether the customer has significant risks and rewards of ownership, and whether the customer has accepted delivery and a right to payment exists. These products are typically sold at prevailing market prices. We allocate variable market-based consideration to deliveries (performance obligations) in the current period as that consideration relates specifically to our efforts to transfer control of current period deliveries to the customer and represents the amount we expect to be entitled to in exchange for the related products. Payment is typically due within 30 days or less. Revenues associated with transactions commonly called buy/sell contracts, in which the purchase and sale of inventory with the same counterparty are entered into “in contemplation” of one another, are combined and reported net (i.e., on the same income statement line).
Cash Equivalents	Cash Equivalents —Cash equivalents are highly liquid, short-term investments that are readily convertible to known amounts of cash and have original maturities of 90 days or less from their date of purchase. They are carried at cost plus accrued interest, which approximates fair value.
Investment, Policy	Short-Term Investments —Short-term investments include investments in bank time deposits and marketable securities (commercial paper and government obligations) which are carried at cost plus accrued interest and have original maturities of greater than 90 days but within one year or when the remaining maturities are within one year. We also invest in financial instruments classified as available for sale debt securities which are carried at fair value. Those instruments are included in short-term investments when they have remaining maturities within one year as of the balance sheet date. Long-Term Investments in Debt Securities —Long-term investments in debt securities includes financial instruments classified as available for sale debt securities with remaining maturities greater than one year as of the balance sheet date. They are carried at fair value and presented within the “Investments and long-term receivables” line of our consolidated balance sheet.
Inventories	Inventories —We have several valuation methods for our various types of inventories and consistently use the following methods for each type of inventory. The majority of our commodity-related inventories are recorded at cost using the LIFO basis. We measure these inventories at the lower-of-cost-or-market in the aggregate. Any necessary lower-of-cost-or-market write-downs at year end are recorded as permanent adjustments to the LIFO cost basis. LIFO is used to better match current inventory costs with current revenues. Costs include both direct and indirect expenditures incurred in bringing an item or product to its existing condition and location, but not unusual/nonrecurring costs or research and development costs. Materials, supplies and other miscellaneous inventories, such as tubular goods and well equipment, are valued using various methods, including the weighted-average-cost method, and the FIFO method, consistent with industry practice.
Fair Value Measurements	Fair Value Measurements —Assets and liabilities measured at fair value and required to be categorized within the fair value hierarchy are categorized into one of three different levels depending on the observability of the inputs employed in the measurement. Level 1 inputs are quoted prices in active markets for identical assets or liabilities. Level 2 inputs are observable inputs other than quoted prices included within Level 1 for the asset or liability, either directly or indirectly through market-corroborated inputs. Level 3 inputs are unobservable inputs for the asset or liability reflecting significant modifications to observable related market data or our assumptions about pricing by market participants.
Derivative Instruments	Derivative Instruments —Derivative instruments are recorded on the balance sheet at fair value. If the right of offset exists and certain other criteria are met, derivative assets and liabilities with the same counterparty are netted on the balance sheet and the collateral payable or receivable is netted against derivative assets and derivative liabilities, respectively. Recognition and classification of the gain or loss that results from recording and adjusting a derivative to fair value depends on the purpose for issuing or holding the derivative. Gains and losses from derivatives not accounted for as hedges are recognized immediately in earnings.
Oil and Gas Exploration and Development	Oil and Gas Exploration and Development —Oil and gas exploration and development costs are accounted for using the successful efforts method of accounting. Property Acquisition Costs —Oil and gas leasehold acquisition costs are capitalized and included in the balance sheet caption PP&E. Leasehold impairment is recognized based on exploratory experience and management’s judgment. Upon achievement of all conditions necessary for reserves to be classified as proved, the associated leasehold costs are reclassified to proved properties. Exploratory Costs —Geological and geophysical costs and the costs of carrying and retaining undeveloped properties are expensed as incurred. Exploratory well costs are capitalized, or “suspended,” on the balance sheet pending further evaluation of whether economically recoverable reserves have been found. If economically recoverable reserves are not found, exploratory well costs are expensed as dry holes. If exploratory wells encounter potentially economic quantities of oil and gas, the well costs remain capitalized on the balance sheet as long as sufficient progress assessing the reserves and the economic and operating viability of the project is being made. For complex exploratory discoveries, it is not unusual to have exploratory wells remain suspended on the balance sheet for several years while we perform additional appraisal drilling and seismic work on the potential oil and gas field or while we seek government or co-venturer approval of development plans or seek environmental permitting. Once all required approvals and permits have been obtained, the projects are moved into the development phase, and the oil and gas resources are designated as proved reserves. Management reviews suspended well balances quarterly, continuously monitors the results of the additional appraisal drilling and seismic work, and expenses the suspended well costs as dry holes when it judges the potential field does not warrant further investment in the near term. See Note 7— Suspended Wells and Exploration Expenses, for additional information on suspended wells. Development Costs —Costs incurred to drill and equip development wells, including unsuccessful development wells, are capitalized. Depletion and Amortization —Leasehold costs of producing properties are depleted using the unit- of-production method based on estimated proved oil and gas reserves. Amortization of intangible development costs is based on the unit-of-production method using estimated proved developed oil and gas reserves. ■ Capitalized Interest —Interest from external borrowings is capitalized on major projects with an expected construction period of one year or longer. Capitalized interest is added to the cost of the underlying asset and is amortized over the useful lives of the assets in the same manner as the underlying assets. ■ Depreciation and Amortization —Depreciation and amortization of PP&E on producing hydrocarbon properties and SAGD facilities and certain pipeline and LNG assets (those which are expected to have a declining utilization pattern), are determined by the unit-of-production method. Depreciation and amortization of all other PP&E are determined by either the individual-unit-straight-line method or the group-straight-line method (for those individual units that are highly integrated with other units). ■ Impairment of Properties, Plants and Equipment —PP&E used in operations are assessed for impairment whenever changes in facts and circumstances indicate a possible significant deterioration in the future cash flows expected to be generated by an asset group. If there is an indication the carrying amount of an asset may not be recovered, a recoverability test is performed using management’s assumptions such as for prices, volumes and future development plans. If, upon review, the sum of the undiscounted cash flows before income-taxes is less than the carrying value of the asset group, the carrying value is written down to estimated fair value and reported as an impairment in the period in which the determination of the impairment is made. Individual assets are grouped for impairment purposes at the lowest level for which there are identifiable cash flows that are largely independent of the cash flows of other groups of assets—generally on a field-by-field basis for E&P assets. Because there usually is a lack of quoted market prices for long-lived assets, the fair value of impaired assets is typically determined based on the present values of expected future cash flows using discount rates and prices believed to be consistent with those used by principal market participants, or based on a multiple of operating cash flow validated with historical market transactions of similar assets where possible. Long- lived assets committed by management for disposal within one year are accounted for at the lower of amortized cost or fair value, less cost to sell, with fair value determined using a binding negotiated price, if available, or present value of expected future cash flows as previously described. The expected future cash flows used for impairment reviews and related fair value calculations are based on estimated future production volumes, prices and costs, considering all available evidence at the date of review. The impairment review includes cash flows from proved developed and undeveloped reserves,
Capitalized Interest	Capitalized Interest —Interest from external borrowings is capitalized on major projects with an expected construction period of one year or longer. Capitalized interest is added to the cost of the underlying asset and is amortized over the useful lives of the assets in the same manner as the underlying assets.
Depreciation and Amortization	Depreciation and Amortization —Depreciation and amortization of PP&E on producing hydrocarbon properties and SAGD facilities and certain pipeline and LNG assets (those which are expected to have a declining utilization pattern), are determined by the unit-of-production method. Depreciation and amortization of all other PP&E are determined by either the individual-unit-straight-line method or the group-straight-line method (for those individual units that are highly integrated with other units).
Impairment of Properties, Plants and Equipment	Impairment of Properties, Plants and Equipment —PP&E used in operations are assessed for impairment whenever changes in facts and circumstances indicate a possible significant deterioration in the future cash flows expected to be generated by an asset group. If there is an indication the carrying amount of an asset may not be recovered, a recoverability test is performed using management’s assumptions such as for prices, volumes and future development plans. If, upon review, the sum of the undiscounted cash flows before income-taxes is less than the carrying value of the asset group, the carrying value is written down to estimated fair value and reported as an impairment in the period in which the determination of the impairment is made. Individual assets are grouped for impairment purposes at the lowest level for which there are identifiable cash flows that are largely independent of the cash flows of other groups of assets—generally on a field-by-field basis for E&P assets. Because there usually is a lack of quoted market prices for long-lived assets, the fair value of impaired assets is typically determined based on the present values of expected future cash flows using discount rates and prices believed to be consistent with those used by principal market participants, or based on a multiple of operating cash flow validated with historical market transactions of similar assets where possible. Long- lived assets committed by management for disposal within one year are accounted for at the lower of amortized cost or fair value, less cost to sell, with fair value determined using a binding negotiated price, if available, or present value of expected future cash flows as previously described. The expected future cash flows used for impairment reviews and related fair value calculations are based on estimated future production volumes, prices and costs, considering all available evidence at the date of review. The impairment review includes cash flows from proved developed and undeveloped reserves, including any development expenditures necessary to achieve that production. Additionally, when probable and possible reserves exist, an appropriate risk-adjusted amount of these reserves may be included in the impairment calculation. ■ Impairment of Investments in Nonconsolidated Entities —Investments in nonconsolidated entities are assessed for impairment whenever changes in the facts and circumstances indicate a loss in value has occurred. When such a condition is judgmentally determined to be other than temporary, the carrying value of the investment is written down to fair value. The fair value of the impaired investment is based on quoted market prices, if available, or upon the present value of expected future cash flows using discount rates and prices believed to be consistent with those used by principal market participants, plus market analysis of comparable assets owned by the investee, if appropriate. ■ Maintenance and Repairs —Costs of maintenance and repairs, which are not significant improvements, are expensed when incurred. ■ Property Dispositions —When complete units of depreciable property are sold, the asset cost and related accumulated depreciation are eliminated, with any gain or loss reflected in the “Gain on dispositions” line of our consolidated income statement. When less than complete units of depreciable property are disposed of or retired which do not significantly alter the DD&A rate, the difference between asset cost and salvage value is charged or credited to accumulated depreciation. ■ Asset Retirement Obligations and Environmental Costs —The fair value of legal obligations to retire and remove long-lived assets are recorded in the period in which the obligation is incurred (typically when the asset is installed at the production location). Fair value is estimated using a present value approach, incorporating assumptions about estimated amounts and timing of settlements and impacts of the use of technologies. When the liability is initially recorded, we capitalize this cost by increasing the carrying amount of the related PP&E. If, in subsequent periods, our estimate of this liability changes, we will record an adjustment to both the liability and PP&E. Over time the liability is increased for the change in its present value, and the capitalized cost in PP&E is depreciated over the useful life of the related asset. Reductions to estimated liabilities for assets that are no longer producing are recorded as a credit to impairment, if the asset had been previously impaired, or as a credit to DD&A, if the asset had not been previously impaired. For additional information, see Note 9—Asset Retirement Obligations and Accrued Environmental Costs. Environmental expenditures are expensed or capitalized, depending upon their future economic benefit. Expenditures relating to an existing condition caused by past operations, and those having no future economic benefit, are expensed. Liabilities for environmental expenditures are recorded on an undiscounted basis (unless acquired through a business combination, which we record on a discounted basis) when environmental assessments or cleanups are probable and the costs can be reasonably estimated. Recoveries of environmental remediation costs from other parties are recorded as assets when their receipt is probable and estimable. ■ Guarantees —The fair value of a guarantee is determined and recorded as a liability at the time the guarantee is given. The initial liability is subsequently reduced as we are released from exposure under the guarantee. We amortize the guarantee liability over the relevant time period, if one exists, based on the facts and circumstances surrounding each type of guarantee. In cases where the guarantee term is indefinite, we reverse the liability when we have information indicating the liability is essentially relieved or amortize it over an appropriate time period as the fair value of our guarantee exposure declines over time. We amortize the guarantee liability to the related income statement line item based on the nature of the guarantee. When it becomes probable that we will have to perform on a guarantee, we accrue a separate liability if it is reasonably estimable, based on the facts and circumstances at that time. We reverse the fair value liability only when there is no further exposure under the guarantee. ■ Share-Based Compensation —We recognize share-based compensation expense over the shorter of the service period (i.e., the stated period of time required to earn the award) or the period beginning at the start of the service period and ending when an employee first becomes eligible for retirement. We have
Impairment of Investments in Nonconsolidated Entities	Impairment of Investments in Nonconsolidated Entities —Investments in nonconsolidated entities are assessed for impairment whenever changes in the facts and circumstances indicate a loss in value has occurred. When such a condition is judgmentally determined to be other than temporary, the carrying value of the investment is written down to fair value. The fair value of the impaired investment is based on quoted market prices, if available, or upon the present value of expected future cash flows using discount rates and prices believed to be consistent with those used by principal market participants, plus market analysis of comparable assets owned by the investee, if appropriate.
Maintenance and Repairs	Maintenance and Repairs —Costs of maintenance and repairs, which are not significant improvements, are expensed when incurred.
Property Dispositions	Property Dispositions —When complete units of depreciable property are sold, the asset cost and related accumulated depreciation are eliminated, with any gain or loss reflected in the “Gain on dispositions” line of our consolidated income statement. When less than complete units of depreciable property are disposed of or retired which do not significantly alter the DD&A rate, the difference between asset cost and salvage value is charged or credited to accumulated depreciation.
Asset Retirement Obligations and Environmental Costs	Asset Retirement Obligations and Environmental Costs —The fair value of legal obligations to retire and remove long-lived assets are recorded in the period in which the obligation is incurred (typically when the asset is installed at the production location). Fair value is estimated using a present value approach, incorporating assumptions about estimated amounts and timing of settlements and impacts of the use of technologies. When the liability is initially recorded, we capitalize this cost by increasing the carrying amount of the related PP&E. If, in subsequent periods, our estimate of this liability changes, we will record an adjustment to both the liability and PP&E. Over time the liability is increased for the change in its present value, and the capitalized cost in PP&E is depreciated over the useful life of the related asset. Reductions to estimated liabilities for assets that are no longer producing are recorded as a credit to impairment, if the asset had been previously impaired, or as a credit to DD&A, if the asset had not been previously impaired. For additional information, see Note 9—Asset Retirement Obligations and Accrued Environmental Costs. Environmental expenditures are expensed or capitalized, depending upon their future economic benefit. Expenditures relating to an existing condition caused by past operations, and those having no future economic benefit, are expensed. Liabilities for environmental expenditures are recorded on an undiscounted basis (unless acquired through a business combination, which we record on a discounted basis) when environmental assessments or cleanups are probable and the costs can be reasonably estimated. Recoveries of environmental remediation costs from other parties are recorded as assets when their receipt is probable and estimable.
Guarantees	Guarantees —The fair value of a guarantee is determined and recorded as a liability at the time the guarantee is given. The initial liability is subsequently reduced as we are released from exposure under the guarantee. We amortize the guarantee liability over the relevant time period, if one exists, based on the facts and circumstances surrounding each type of guarantee. In cases where the guarantee term is indefinite, we reverse the liability when we have information indicating the liability is essentially relieved or amortize it over an appropriate time period as the fair value of our guarantee exposure declines over time. We amortize the guarantee liability to the related income statement line item based on the nature of the guarantee. When it becomes probable that we will have to perform on a guarantee, we accrue a separate liability if it is reasonably estimable, based on the facts and circumstances at that time. We reverse the fair value liability only when there is no further exposure under the guarantee.
Stock-Based Compensation	Share-Based Compensation —We recognize share-based compensation expense over the shorter of the service period (i.e., the stated period of time required to earn the award) or the period beginning at the start of the service period and ending when an employee first becomes eligible for retirement. We have elected to recognize expense on a straight-line basis over the service period for the entire award, whether the award was granted with ratable or cliff vesting. ■ Income Taxes —Deferred income taxes are computed using the liability method and are provided on all temporary differences between the financial reporting basis and the tax basis of our assets and liabilities, except for deferred taxes on income and temporary differences related to the cumulative translation adjustment considered to be permanently reinvested in certain foreign subsidiaries and foreign corporate joint ventures. Allowable tax credits are applied currently as reductions of the provision for income taxes. Interest related to unrecognized tax benefits is reflected in interest and debt expense, and penalties related to unrecognized tax benefits are reflected in production and operating expenses. ■ Taxes Collected from Customers and Remitted to Governmental Authorities —Sales and value- added taxes are recorded net. ■ Net Income (Loss) Per Share of Common Stock —Basic net income (loss) per share of common stock is calculated based upon the daily weighted-average number of common shares outstanding during the year. Also, this calculation includes fully vested stock and unit awards that have not yet been issued as common stock, along with an adjustment to net income (loss) for dividend equivalents paid on unvested unit awards that are considered participating securities. Diluted net income per share of common stock includes unvested stock, unit or option awards granted under our compensation plans and vested but unexercised stock options, but only to the extent these instruments dilute net income per share, primarily under the treasury-stock method. Diluted net loss per share, which is calculated the same as basic net loss per share, does not assume conversion or exercise of securities that would have an antidilutive effect. Treasury stock is excluded from the daily weighted-average number of common shares outstanding in both calculations. The earnings per share impact of the participating securities is immaterial.
Income Taxes	Income Taxes —Deferred income taxes are computed using the liability method and are provided on all temporary differences between the financial reporting basis and the tax basis of our assets and liabilities, except for deferred taxes on income and temporary differences related to the cumulative translation adjustment considered to be permanently reinvested in certain foreign subsidiaries and foreign corporate joint ventures. Allowable tax credits are applied currently as reductions of the provision for income taxes. Interest related to unrecognized tax benefits is reflected in interest and debt expense, and penalties related to unrecognized tax benefits are reflected in production and operating expenses.
Taxes Collected from Customers and Remitted to Governmental Authorities	Taxes Collected from Customers and Remitted to Governmental Authorities —Sales and value- added taxes are recorded net.
Net Income (Loss) Per Share of Common Stock	Net Income (Loss) Per Share of Common Stock —Basic net income (loss) per share of common stock is calculated based upon the daily weighted-average number of common shares outstanding during the year. Also, this calculation includes fully vested stock and unit awards that have not yet been issued as common stock, along with an adjustment to net income (loss) for dividend equivalents paid on unvested unit awards that are considered participating securities. Diluted net income per share of common stock includes unvested stock, unit or option awards granted under our compensation plans and vested but unexercised stock options, but only to the extent these instruments dilute net income per share, primarily under the treasury-stock method. Diluted net loss per share, which is calculated the same as basic net loss per share, does not assume conversion or exercise of securities that would have an antidilutive effect. Treasury stock is excluded from the daily weighted-average number of common shares outstanding in both calculations. The earnings per share impact of the participating securities is immaterial.
Shipping and Handling Cost, Policy [Policy Text Block]	Shipping and Handling Costs —We typically incur shipping and handling costs prior to control transferring to the customer and account for these activities as fulfillment costs. Accordingly, we include shipping and handling costs in production and operating expenses for production activities. Transportation costs related to marketing activities are recorded in purchased commodities. Freight costs billed to customers are treated as a component of the transaction price and recorded as a component of revenue when the customer obtains control.
New Accounting Pronouncements, Policy [Policy Text Block]	We adopted the provisions of FASB ASU No. 2016-13, “Measurement of Credit Losses on Financial Instruments,” (ASC Topic 326) and its amendments, beginning January 1, 2020. This ASU, as amended, sets forth the current expected credit loss model, a new forward-looking impairment model for certain financial instruments measured at amortized cost basis based on expected losses rather than incurred losses. This ASU, as amended, which primarily applies to our accounts receivable, also requires credit losses related to available- for-sale debt securities to be recorded through an allowance for credit losses. The adoption of this ASU did not have a material impact to our financial statements. The majority of our receivables are due within 30 days or less. We monitor the credit quality of our counterparties through review of collections, credit ratings, and other analyses. We develop our estimated allowance for credit losses primarily using an aging method and analyses of historical loss rates as well as consideration of current and future conditions that could impact our counterparties’ credit quality and liquidity.

Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Consolidation Principles and Investments

—Our consolidated financial statements

include the accounts

of majority-owned, controlled subsidiaries

and variable interest entities where we are the primary

beneficiary.

The equity method is used to account for

investments in affiliates in which we have the

ability to exert significant influence over the affiliates’

operating and financial policies.

When we do not

have the ability to exert significant influence,

the investment is measured at fair value

except when the

investment does not have a readily determinable

fair value.

For those exceptions, it will be measured

cost minus impairment, plus or minus observable

price changes in orderly transactions for an identical

similar investment of the same issuer.

Undivided interests in oil and gas joint ventures,

pipelines, natural

gas plants and terminals are consolidated on a proportionate

basis.

Other securities and investments are

generally carried at cost.

We manage our operations through six operating segments, defined by geographic

region: Alaska; Lower

48; Canada;

Europe,

Middle East and North Africa; Asia Pacific;

and Other International.

For additional

information, see Note 24—Segment Disclosures

and Related Information.

The unrealized (gain) loss on investment in Cenovus

Energy included on our consolidated statement of

cash flows, previously reflected on the line item

“Other” within net cash provided by operating

activities,

has been reclassified in the comparative periods

to conform with the current period’s presentation.

Foreign Currency Translation

—Adjustments resulting from the process of translating

foreign

functional currency financial statements into

U.S. dollars are included in accumulated other

comprehensive loss in common stockholders’ equity.

Foreign currency transaction gains and losses

are

included in current earnings.

Some of our foreign operations use their local currency

as the functional

currency.

Use of Estimates

—The preparation of financial statements

in conformity with accounting principles

generally accepted in the U.S. requires management

to make estimates and assumptions that

affect the

reported amounts of assets, liabilities,

revenues and expenses, and the disclosures of contingent

assets and

liabilities.

Actual results could differ from these estimates.

Revenue Recognition

—Revenues associated with the sales of crude

oil, bitumen, natural gas, LNG,

NGLs and other items are recognized at the point

in time when the customer obtains control

of the asset.

In evaluating when a customer has control of the

asset, we primarily consider whether

the transfer of legal

title and physical delivery has occurred, whether

the customer has significant risks and rewards

ownership, and whether the customer has accepted

delivery and a right to payment exists.

These products

are typically sold at prevailing market prices.

We allocate variable market-based consideration to

deliveries (performance obligations) in the

current period as that consideration relates

specifically to our

efforts to transfer control of current period deliveries to the

customer and represents the amount we

expect to be entitled to in exchange for the related

products.

Payment is typically due within 30 days or

less.

Revenues associated with transactions commonly

called buy/sell contracts, in which the

purchase and sale

of inventory with the same counterparty are entered

into “in contemplation” of one another, are combined

and reported net (i.e., on the same income statement

line).

Cash Equivalents

—Cash equivalents are highly liquid,

short-term investments that are readily

convertible to known amounts of cash and have

original maturities of 90 days or less from

their date of

purchase.

They are carried at cost plus accrued interest,

which approximates fair value.

Investment, Policy

Short-Term Investments

—Short-term investments include investments

in bank time deposits and

marketable securities (commercial paper and government

obligations) which are carried at cost plus

accrued interest and have original maturities

of greater than 90 days but within one year or

when the

remaining maturities are within one year.

We also invest in financial instruments classified as available

for sale debt securities which are carried at fair

value. Those instruments are included in short-term

investments when they have remaining maturities

within one year as of the balance sheet date.

Long-Term Investments in Debt Securities

—Long-term investments in debt securities

includes

financial instruments classified as available for sale

debt securities with remaining maturities

greater than

one year as of the balance sheet date.

They are carried at fair value and presented

within the “Investments

and long-term receivables” line of our consolidated

balance sheet.

Inventories

—We have several valuation methods for our various types of inventories

and consistently

use the following methods for each type of inventory.

The majority of our commodity-related inventories

are recorded at cost using the LIFO basis.

We measure these inventories at the lower-of-cost-or-market in

the aggregate.

Any necessary lower-of-cost-or-market write-downs at year

end are recorded as

permanent adjustments to the LIFO cost basis.

LIFO is used to better match current inventory

costs with

current revenues.

Costs include both direct and indirect expenditures

incurred in bringing an item or

product to its existing condition and location,

but not unusual/nonrecurring costs or research

and

development costs.

Materials, supplies and other miscellaneous inventories,

such as tubular goods and

well equipment, are valued using various methods,

including the weighted-average-cost

method, and the

FIFO method, consistent with industry practice.

Fair Value Measurements

—Assets and liabilities measured at fair value

and required to be categorized

within the fair value hierarchy are categorized into

one of three different levels depending on the

observability of the inputs employed in the measurement.

Level 1 inputs are quoted prices in active

markets for identical assets or liabilities.

Level 2 inputs are observable inputs other than

quoted prices

included within Level 1 for the asset or liability, either directly or indirectly

through market-corroborated

inputs.

Level 3 inputs are unobservable inputs for

the asset or liability reflecting significant

modifications

to observable related market data or our assumptions

about pricing by market participants.

Derivative Instruments

—Derivative instruments are recorded on the balance

sheet at fair value.

If the

right of offset exists and certain other criteria are met,

derivative assets and liabilities with the same

counterparty are netted on the balance sheet and the

collateral payable or receivable is netted

against

derivative assets and derivative liabilities,

respectively.

Recognition and classification of the gain or loss

that results from recording and adjusting

a derivative to

fair value depends on the purpose for issuing or

holding the derivative.

Gains and losses from derivatives

not accounted for as hedges are recognized immediately

in earnings.

Oil and Gas Exploration and Development

—Oil and gas exploration and development

costs are

accounted for using the successful efforts method of

accounting.

Property Acquisition Costs

—Oil and gas leasehold acquisition costs are

capitalized and included in

the balance sheet caption PP&E.

Leasehold impairment is recognized based

on exploratory

experience and management’s judgment.

Upon achievement of all conditions necessary for reserves

to be classified as proved, the associated leasehold

costs are reclassified to proved properties.

Exploratory Costs

—Geological and geophysical costs and the

costs of carrying and retaining

undeveloped properties are expensed as incurred.

Exploratory well costs are capitalized, or

“suspended,” on the balance sheet pending further

evaluation of whether economically recoverable

reserves have been found.

If economically recoverable reserves are not found,

exploratory well costs

are expensed as dry holes.

If exploratory wells encounter potentially

economic quantities of oil and

gas, the well costs remain capitalized on the balance

sheet as long as sufficient progress assessing the

reserves and the economic and operating viability

of the project is being made.

For complex

exploratory discoveries, it is not unusual to

have exploratory wells remain suspended

on the balance

sheet for several years while we perform additional

appraisal drilling and seismic work on the

potential oil and gas field or while we seek government

or co-venturer approval of development plans

or seek environmental permitting.

Once all required approvals and permits have been

obtained, the

projects are moved into the development phase,

and the oil and gas resources are designated

as proved

reserves.

Management reviews suspended well balances quarterly, continuously monitors

the results of the

additional appraisal drilling and seismic work,

and expenses the suspended well costs

as dry holes

when it judges the potential field does not

warrant further investment in the near term.

See Note 7—

Suspended Wells and Exploration Expenses, for additional information on suspended

wells.

Development Costs

—Costs incurred to drill and equip development

wells, including unsuccessful

development wells, are capitalized.

Depletion and Amortization

—Leasehold costs of producing properties

are depleted using the unit-

of-production method based on estimated proved

oil and gas reserves.

Amortization of intangible

development costs is based on the unit-of-production

method using estimated proved developed

oil

and gas reserves.

■

Capitalized Interest

—Interest from external borrowings is

capitalized on major projects with an

expected construction period of one year or longer.

Capitalized interest is added to the cost of the

underlying asset and is amortized over the useful

lives of the assets in the same manner

as the underlying

assets.

■

Depreciation and Amortization

—Depreciation and amortization of PP&E

on producing hydrocarbon

properties and SAGD facilities and certain pipeline

and LNG assets (those which are expected

to have a

declining utilization pattern), are determined by

the unit-of-production method.

Depreciation and

amortization of all other PP&E are determined

by either the individual-unit-straight-line method

or the

group-straight-line method (for those individual

units that are highly integrated with other

units).

■

Impairment of Properties, Plants and Equipment

—PP&E used in operations are assessed for

impairment whenever changes in facts and circumstances

indicate a possible significant deterioration

the future cash flows expected to be generated

by an asset group.

If there is an indication the carrying

amount of an asset may not be recovered, a recoverability

test is performed using management’s

assumptions such as for prices, volumes and future

development plans.

If, upon review, the sum of the

undiscounted cash flows before income-taxes is

less than the carrying value of the asset

group, the

carrying value is written down to estimated fair

value and reported as an impairment in the

period in

which the determination of the impairment

is made.

Individual assets are grouped for impairment

purposes at the lowest level for which there are

identifiable cash flows that are largely independent

of the

cash flows of other groups of assets—generally

on a field-by-field basis for E&P assets.

Because there

usually is a lack of quoted market prices for

long-lived assets, the fair value of impaired assets

is typically

determined based on the present values of expected

future cash flows using discount rates

and prices

believed to be consistent with those used by principal

market participants, or based on a multiple

operating cash flow validated with historical

market transactions of similar assets

where possible.

Long-

lived assets committed by management for disposal

within one year are accounted for at

the lower of

amortized cost or fair value, less cost to sell,

with fair value determined using a binding negotiated

price,

if available, or present value of expected future

cash flows as previously described.

The expected future cash flows used for impairment

reviews and related fair value calculations are

based

on estimated future production volumes, prices

and costs, considering all available evidence at the

date of

review.

The impairment review includes cash flows from

proved developed and undeveloped reserves,

Capitalized Interest

—Interest from external borrowings is

capitalized on major projects with an

expected construction period of one year or longer.

Capitalized interest is added to the cost of the

underlying asset and is amortized over the useful

lives of the assets in the same manner

as the underlying

assets.

Depreciation and Amortization

—Depreciation and amortization of PP&E

on producing hydrocarbon

properties and SAGD facilities and certain pipeline

and LNG assets (those which are expected

to have a

declining utilization pattern), are determined by

the unit-of-production method.

Depreciation and

amortization of all other PP&E are determined

by either the individual-unit-straight-line method

or the

group-straight-line method (for those individual

units that are highly integrated with other

units).

Impairment of Properties, Plants and Equipment

—PP&E used in operations are assessed for

impairment whenever changes in facts and circumstances

indicate a possible significant deterioration

the future cash flows expected to be generated

by an asset group.

If there is an indication the carrying

amount of an asset may not be recovered, a recoverability

test is performed using management’s

assumptions such as for prices, volumes and future

development plans.

If, upon review, the sum of the

undiscounted cash flows before income-taxes is

less than the carrying value of the asset

group, the

carrying value is written down to estimated fair

value and reported as an impairment in the

period in

which the determination of the impairment

is made.

Individual assets are grouped for impairment

purposes at the lowest level for which there are

identifiable cash flows that are largely independent

of the

cash flows of other groups of assets—generally

on a field-by-field basis for E&P assets.

Because there

usually is a lack of quoted market prices for

long-lived assets, the fair value of impaired assets

is typically

determined based on the present values of expected

future cash flows using discount rates

and prices

believed to be consistent with those used by principal

market participants, or based on a multiple

operating cash flow validated with historical

market transactions of similar assets

where possible.

Long-

lived assets committed by management for disposal

within one year are accounted for at

the lower of

amortized cost or fair value, less cost to sell,

with fair value determined using a binding negotiated

price,

if available, or present value of expected future

cash flows as previously described.

The expected future cash flows used for impairment

reviews and related fair value calculations are

based

on estimated future production volumes, prices

and costs, considering all available evidence at the

date of

review.

The impairment review includes cash flows from

proved developed and undeveloped reserves,

including any development expenditures necessary

to achieve that production.

Additionally, when

probable and possible reserves exist, an appropriate

risk-adjusted amount of these reserves may be

included in the impairment calculation.

■

Impairment of Investments in Nonconsolidated

Entities

—Investments in nonconsolidated entities

are

assessed for impairment whenever changes in the

facts and circumstances indicate a loss

in value has

occurred.

When such a condition is judgmentally determined

to be other than temporary, the carrying

value of the investment is written down to fair

value.

The fair value of the impaired investment

is based

on quoted market prices, if available, or upon

the present value of expected future cash flows using

discount rates and prices believed to be consistent

with those used by principal market participants,

plus

market analysis of comparable assets owned by the

investee, if appropriate.

■

Maintenance and Repairs

—Costs of maintenance and repairs, which are

not significant improvements,

are expensed when incurred.

■

Property Dispositions

—When complete units of depreciable property

are sold, the asset cost and related

accumulated depreciation are eliminated,

with any gain or loss reflected in the “Gain on dispositions”

line

of our consolidated income statement.

When less than complete units of depreciable property

are

disposed of or retired which do not significantly

alter the DD&A rate, the difference between asset

cost

and salvage value is charged or credited to accumulated

depreciation.

■

Asset Retirement Obligations and Environmental Costs

—The

fair value of legal obligations to retire

and remove long-lived assets are recorded in

the period in which the obligation is incurred

(typically

when the asset is installed at the production location).

Fair value is estimated using a present value

approach, incorporating assumptions about estimated

amounts and timing of settlements and

impacts of

the use of technologies.

When the liability is initially recorded,

we capitalize this cost by increasing the

carrying amount of the related PP&E.

If, in subsequent periods, our estimate of this

liability changes, we

will record an adjustment to both the liability

and PP&E.

Over time the liability is increased for the

change in its present value, and the capitalized cost

in PP&E is depreciated over the useful

life of the

related asset.

Reductions to estimated liabilities for

assets that are no longer producing are recorded as a

credit to impairment, if the asset had been previously

impaired, or as a credit to DD&A, if the

asset had

not been previously impaired.

For additional information, see Note 9—Asset

Retirement Obligations and

Accrued Environmental Costs.

Environmental expenditures are expensed or capitalized,

depending upon their future economic benefit.

Expenditures relating to an existing condition

caused by past operations, and those having no future

economic benefit, are expensed.

Liabilities for environmental expenditures are

recorded on an

undiscounted basis (unless acquired through a business

combination, which we record on a discounted

basis) when environmental assessments or cleanups

are probable and the costs can be reasonably

estimated.

Recoveries of environmental remediation costs

from other parties are recorded as assets when

their receipt is probable and estimable.

■

Guarantees

—The fair value of a guarantee is determined

and recorded as a liability at the time the

guarantee is given.

The initial liability is subsequently reduced

as we are released from exposure under

the guarantee.

We amortize the guarantee liability over the relevant time period, if one exists, based on

the facts and circumstances surrounding each type

of guarantee.

In cases where the guarantee term is

indefinite, we reverse the liability when we have

information indicating the liability

is essentially relieved

or amortize it over an appropriate time

period as the fair value of our guarantee exposure

declines over

time.

We amortize the guarantee liability to the related income statement line item based

on the nature of

the guarantee.

When it becomes probable that we will have

to perform on a guarantee, we accrue a

separate liability if it is reasonably estimable,

based on the facts and circumstances at that

time.

reverse the fair value liability only when there

is no further exposure under the guarantee.

■

Share-Based Compensation

—We recognize share-based compensation expense over the shorter of the

service period (i.e., the stated period of time required

to earn the award) or the period beginning at

the

start of the service period and ending when an

employee first becomes eligible for retirement.

We have

Impairment of Investments in Nonconsolidated Entities

Impairment of Investments in Nonconsolidated

Entities

—Investments in nonconsolidated entities

are

assessed for impairment whenever changes in the

facts and circumstances indicate a loss

in value has

occurred.

When such a condition is judgmentally determined

to be other than temporary, the carrying

value of the investment is written down to fair

value.

The fair value of the impaired investment

is based

on quoted market prices, if available, or upon

the present value of expected future cash flows using

discount rates and prices believed to be consistent

with those used by principal market participants,

plus

market analysis of comparable assets owned by the

investee, if appropriate.

Maintenance and Repairs

—Costs of maintenance and repairs, which are

not significant improvements,

are expensed when incurred.

Property Dispositions

—When complete units of depreciable property

are sold, the asset cost and related

accumulated depreciation are eliminated,

with any gain or loss reflected in the “Gain on dispositions”

line

of our consolidated income statement.

When less than complete units of depreciable property

are

disposed of or retired which do not significantly

alter the DD&A rate, the difference between asset

cost

and salvage value is charged or credited to accumulated

depreciation.

Asset Retirement Obligations and Environmental Costs

—The

fair value of legal obligations to retire

and remove long-lived assets are recorded in

the period in which the obligation is incurred

(typically

when the asset is installed at the production location).

Fair value is estimated using a present value

approach, incorporating assumptions about estimated

amounts and timing of settlements and

impacts of

the use of technologies.

When the liability is initially recorded,

we capitalize this cost by increasing the

carrying amount of the related PP&E.

If, in subsequent periods, our estimate of this

liability changes, we

will record an adjustment to both the liability

and PP&E.

Over time the liability is increased for the

change in its present value, and the capitalized cost

in PP&E is depreciated over the useful

life of the

related asset.

Reductions to estimated liabilities for

assets that are no longer producing are recorded as a

credit to impairment, if the asset had been previously

impaired, or as a credit to DD&A, if the

asset had

not been previously impaired.

For additional information, see Note 9—Asset

Retirement Obligations and

Accrued Environmental Costs.

Environmental expenditures are expensed or capitalized,

depending upon their future economic benefit.

Expenditures relating to an existing condition

caused by past operations, and those having no future

economic benefit, are expensed.

Liabilities for environmental expenditures are

recorded on an

undiscounted basis (unless acquired through a business

combination, which we record on a discounted

basis) when environmental assessments or cleanups

are probable and the costs can be reasonably

estimated.

Recoveries of environmental remediation costs

from other parties are recorded as assets when

their receipt is probable and estimable.

Guarantees

—The fair value of a guarantee is determined

and recorded as a liability at the time the

guarantee is given.

The initial liability is subsequently reduced

as we are released from exposure under

the guarantee.

We amortize the guarantee liability over the relevant time period, if one exists, based on

the facts and circumstances surrounding each type

of guarantee.

In cases where the guarantee term is

indefinite, we reverse the liability when we have

information indicating the liability

is essentially relieved

or amortize it over an appropriate time

period as the fair value of our guarantee exposure

declines over

time.

We amortize the guarantee liability to the related income statement line item based

on the nature of

the guarantee.

When it becomes probable that we will have

to perform on a guarantee, we accrue a

separate liability if it is reasonably estimable,

based on the facts and circumstances at that

time.

reverse the fair value liability only when there

is no further exposure under the guarantee.

Stock-Based Compensation

Share-Based Compensation

—We recognize share-based compensation expense over the shorter of the

service period (i.e., the stated period of time required

to earn the award) or the period beginning at

the

start of the service period and ending when an

employee first becomes eligible for retirement.

We have

elected to recognize expense on a straight-line

basis over the service period for the entire

award, whether

the award was granted with ratable or cliff vesting.

■

Income Taxes

—Deferred income taxes are computed using

the liability method and are provided on all

temporary differences between the financial reporting basis

and the tax basis of our assets and liabilities,

except for deferred taxes on income and temporary

differences related to the cumulative translation

adjustment considered to be permanently reinvested

in certain foreign subsidiaries and

foreign corporate

joint ventures.

Allowable tax credits are applied currently

as reductions of the provision for income

taxes.

Interest related to unrecognized tax benefits

is reflected in interest and debt expense, and

penalties

related to unrecognized tax benefits are reflected

in production and operating expenses.

■

Taxes Collected from Customers and Remitted to Governmental Authorities

—Sales and value-

added taxes are recorded net.

■

Net Income (Loss) Per Share of Common Stock

—Basic net income (loss) per share of common stock

is calculated based upon the daily weighted-average

number of common shares outstanding during

the

year.

Also, this

calculation includes fully vested stock and unit

awards that have not yet been issued as

common stock, along with an adjustment to

net income (loss) for dividend equivalents

paid on unvested

unit awards that are considered participating

securities.

Diluted net income per share of common stock

includes unvested stock, unit or option awards granted

under our compensation plans and vested but

unexercised stock options, but only to the extent these

instruments dilute net income per share, primarily

under the treasury-stock method.

Diluted net loss per share, which is calculated

the same as basic net loss

per share, does not assume conversion or exercise

of securities that would have an antidilutive

effect.

Treasury stock is excluded from the daily weighted-average number

of common shares outstanding in

both calculations.

The earnings per share impact of the participating

securities is immaterial.

Income Taxes

—Deferred income taxes are computed using

the liability method and are provided on all

temporary differences between the financial reporting basis

and the tax basis of our assets and liabilities,

except for deferred taxes on income and temporary

differences related to the cumulative translation

adjustment considered to be permanently reinvested

in certain foreign subsidiaries and

foreign corporate

joint ventures.

Allowable tax credits are applied currently

as reductions of the provision for income

taxes.

Interest related to unrecognized tax benefits

is reflected in interest and debt expense, and

penalties

related to unrecognized tax benefits are reflected

in production and operating expenses.

Taxes Collected from Customers and Remitted to Governmental Authorities

—Sales and value-

added taxes are recorded net.

Net Income (Loss) Per Share of Common Stock

—Basic net income (loss) per share of common stock

is calculated based upon the daily weighted-average

number of common shares outstanding during

the

year.

Also, this

calculation includes fully vested stock and unit

awards that have not yet been issued as

common stock, along with an adjustment to

net income (loss) for dividend equivalents

paid on unvested

unit awards that are considered participating

securities.

Diluted net income per share of common stock

includes unvested stock, unit or option awards granted

under our compensation plans and vested but

unexercised stock options, but only to the extent these

instruments dilute net income per share, primarily

under the treasury-stock method.

Diluted net loss per share, which is calculated

the same as basic net loss

per share, does not assume conversion or exercise

of securities that would have an antidilutive

effect.

Treasury stock is excluded from the daily weighted-average number

of common shares outstanding in

both calculations.

The earnings per share impact of the participating

securities is immaterial.

Shipping and Handling Cost, Policy [Policy Text Block]

Shipping and Handling Costs

—We typically incur shipping and handling costs prior to control

transferring to the customer and account for these

activities as fulfillment costs.

Accordingly, we include

shipping and handling costs in production and operating

expenses for production activities.

Transportation costs related to marketing activities are recorded

in purchased commodities.

Freight costs

billed to customers are treated as a component of the

transaction price and recorded as a component

revenue when the customer obtains control.

New Accounting Pronouncements, Policy [Policy Text Block]

We adopted the provisions of FASB ASU No. 2016-13, “Measurement of Credit Losses on Financial

Instruments,” (ASC Topic 326) and its amendments, beginning January 1, 2020. This ASU, as amended, sets

forth the current expected credit loss model, a new forward-looking impairment model for certain financial

instruments measured at amortized cost basis based on expected losses rather than incurred losses. This ASU,

as amended, which primarily applies to our accounts receivable, also requires credit losses related to available-

for-sale debt securities to be recorded through an allowance for credit losses. The adoption of this ASU did

not have a material impact to our financial statements. The majority of our receivables are due within 30 days

or less. We monitor the credit quality of our counterparties through review of collections, credit ratings, and

other analyses. We develop our estimated allowance for credit losses primarily using an aging method and

analyses of historical loss rates as well as consideration of current and future conditions that could impact our

counterparties’ credit quality and liquidity.