| Revenue | $12.7B | $11.7B | $12.7B | $14.5B | $12.6B | $13.3B | $11.4B | $13.5B |
| Other | — | — | — | $7.1B | — | — | — | $7.4B |
| Segment Reporting, Other Segment Item, Amount | $5.5B | $5.2B | $6.3B | $6.8B | $5.6B | $6.6B | $5.5B | $7.2B |
| Significant Segment Expenses | $5.8B | $5.8B | $5.6B | $6.9B | $6.5B | $6.8B | $6.4B | $6.4B |
| Cash Provided by (Used in) Operating Activity, Including Discontinued Operation | $4.9B | $5.8B | $4.5B | $6.1B | $3.5B | $5.9B | $4.3B | $4.3B |
| Payment To Acquire Productive Assets And Investments | $3.0B | $2.9B | $3.3B | $3.4B | $3.3B | $2.9B | $3.0B | $2.9B |
| Capital expenditures and investments | $3.0B | $2.9B | $3.3B | $3.4B | $3.3B | $2.9B | $3.0B | $2.9B |
| Cash Provided by (Used in) Investing Activity, Including Discontinued Operation | -$4.2B | -$2.7B | -$2.2B | -$2.3B | -$2.5B | -$3.2B | -$850.0M | -$2.8B |
| Cash Provided by (Used in) Financing Activity, Including Discontinued Operation | -$2.0B | -$2.2B | -$1.8B | -$3.1B | -$2.5B | -$2.3B | -$2.2B | -$2.2B |
| Reclassifications Net of Tax | $2.3B | $2.1B | $2.3B | $2.8B | $2.0B | $1.7B | $1.4B | $2.2B |
| Comprehensive Income (Loss), Net of Tax, Attributable to Parent | $2.3B | $2.2B | $1.7B | $2.9B | $2.5B | $1.6B | $1.6B | $2.1B |
| Other Comprehensive Income (Loss) | $2.3B | $2.2B | $1.7B | $2.9B | $2.5B | $1.6B | $1.6B | $2.1B |
| Dividends, Common Stock | $680.0M | $677.0M | $897.0M | $998.0M | $984.0M | $975.0M | $1.0B | $1.0B |
| Payments of Ordinary Dividends, Common Stock | $915.0M | $910.0M | $897.0M | $998.0M | $984.0M | $975.0M | $1.0B | $1.0B |
| Cash Dividends, Common Stock | $915.0M | $910.0M | $897.0M | $998.0M | $984.0M | $975.0M | $1.0B | $1.0B |
| Payments for Repurchase of Common Stock | $1.0B | $1.2B | $2.0B | $1.5B | $1.2B | $1.3B | $1.0B | $1.0B |
| Treasury stock, value, acquired | $1.0B | $1.2B | $2.0B | $1.5B | $1.2B | $1.3B | $1.0B | $1.0B |
| Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation | — | — | — | $715.0M | — | — | — | -$670.0M |
| Income Taxes Paid, Net | $1.4B | $730.0M | $824.0M | $1.2B | $2.0B | $698.0M | $926.0M | $669.0M |
| Income Taxes Paid, Net | $1.4B | $730.0M | $824.0M | $1.2B | $2.0B | $698.0M | $926.0M | $669.0M |
| Taxes other than income taxes and other – net | $536.0M | $476.0M | $520.0M | $551.0M | $572.0M | $525.0M | $498.0M | $607.0M |
| Accounts payable | -$98.0M | — | -$426.0M | $518.0M | -$545.0M | -$184.0M | -$1.0M | $507.0M |
| Increase (Decrease) in Other Operating Assets and Liabilities, Net | $51.0M | -$416.0M | -$218.0M | -$10.0M | $1.2B | — | — | $324.0M |
| Interest Paid, Net | $150.0M | $224.0M | $178.0M | $214.0M | $111.0M | $369.0M | $63.0M | $296.0M |
| Interest Paid, Excluding Capitalized Interest, Operating Activity | $150.0M | $224.0M | $178.0M | $214.0M | $111.0M | $369.0M | $63.0M | $296.0M |
| Payments for Restructuring | — | — | — | — | — | — | — | $248.0M |
| Payments to Acquire Long-Term Investments | $148.0M | $156.0M | $244.0M | $192.0M | $267.0M | $216.0M | $186.0M | $232.0M |
| Proceeds from sales and redemptions of investments in debt securities classified as available for sale | $231.0M | $142.0M | $271.0M | $211.0M | $300.0M | $271.0M | $180.0M | $209.0M |
| Interest and Debt Expense | $198.0M | $189.0M | $191.0M | $205.0M | $232.0M | $223.0M | $195.0M | $198.0M |
| Increase decrease in capital accrual | $4.0M | $22.0M | $107.0M | $827.0M | — | — | $58.0M | $162.0M |
| Short-term investments sold | $298.0M | $1.4B | $1.2B | $158.0M | $636.0M | $342.0M | $615.0M | $162.0M |
| Other Comprehensive Income (Loss), Net of Tax | -$44.0M | $116.0M | -$628.0M | $79.0M | $492.0M | -$172.0M | $163.0M | -$117.0M |
| OCI Attributable to Parent | -$44.0M | $116.0M | -$628.0M | $79.0M | $492.0M | -$172.0M | $163.0M | -$117.0M |
| Other comprehensive income/(loss) | -$44.0M | $116.0M | -$628.0M | $79.0M | $492.0M | -$172.0M | $163.0M | -$117.0M |
| Other Comprehensive Income (Loss), Net of Tax, Attributable to Parent | -$44.0M | $116.0M | -$628.0M | $79.0M | $492.0M | -$172.0M | $163.0M | -$117.0M |
| OCI Net of Tax, Parent | -$44.0M | $116.0M | -$628.0M | $79.0M | $492.0M | -$172.0M | $163.0M | -$117.0M |
| Repayments of Debt | $58.0M | $44.0M | $4.4B | $547.0M | $259.0M | $45.0M | $62.0M | $114.0M |
| Deferred taxes | $124.0M | $38.0M | $118.0M | -$71.0M | $149.0M | $354.0M | $117.0M | $102.0M |
| OCI Foreign Currency Before Reclassification and Tax | -$73.0M | $147.0M | -$604.0M | $70.0M | $484.0M | -$180.0M | — | -$95.0M |
| OCI Foreign Currency Gain (Loss) Before Reclassification and Tax | -$73.0M | $147.0M | -$604.0M | $70.0M | $484.0M | -$180.0M | — | -$95.0M |
| Increase (Decrease) in Prepaid Expense and Other Assets | $221.0M | -$94.0M | -$132.0M | $134.0M | $95.0M | — | — | $95.0M |
| Foreign Currency Translation Adjustments, Net | -$73.0M | $147.0M | -$604.0M | $70.0M | $484.0M | -$180.0M | — | -$95.0M |
| OCI Foreign Currency Gain (Loss), Pre-tax | -$73.0M | $147.0M | -$604.0M | $70.0M | $484.0M | -$180.0M | — | -$95.0M |
| Retired debt | — | — | — | — | — | — | — | $67.0M |
| Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount | — | — | — | -$56.0M | -$56.0M | — | — | -$56.0M |
| Long-term Investments sold | $35.0M | $25.0M | $92.0M | $53.0M | $65.0M | $95.0M | $91.0M | $47.0M |
| All other operating activities | $76.0M | -$28.0M | $148.0M | -$115.0M | — | -$141.0M | -$16.0M | $44.0M |
| Other income, net | $118.0M | $124.0M | $96.0M | $113.0M | $104.0M | $143.0M | $178.0M | $41.0M |
| Increase (Decrease) in Inventories | $2.0M | $43.0M | — | $26.0M | $58.0M | -$133.0M | $165.0M | $39.0M |
| Net pension liability increase | — | — | — | — | — | — | — | $39.0M |
| Proceeds from Issuance of Common Stock | $0.0 | -$9.0M | -$12.0M | -$52.0M | -$3.0M | -$10.0M | -$35.0M | -$35.0M |
| Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture | $81.0M | $49.0M | $62.0M | $25.0M | $89.0M | $58.0M | $27.0M | $33.0M |
| Payments For Proceeds From Investments | $1.2B | -$195.0M | -$1.0B | $400.0M | — | $548.0M | — | $30.0M |
| Effect of exchange rate changes on cash, cash equivalents and restricted cash | — | — | — | $83.0M | — | — | — | $29.0M |
| OCI - Defined benefit plan, net of tax | -$4.0M | -$5.0M | — | -$7.0M | -$6.0M | -$7.0M | -$35.0M | $16.0M |
| Other Comprehensive Income (Loss) | -$4.0M | -$5.0M | — | -$7.0M | -$6.0M | -$7.0M | -$35.0M | $16.0M |
| OCI Defined Benefit Plan Net of Tax | -$4.0M | -$5.0M | — | -$7.0M | -$6.0M | -$7.0M | -$35.0M | $16.0M |
| Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax | -$4.0M | -$5.0M | — | -$7.0M | -$6.0M | -$7.0M | -$35.0M | $16.0M |
| OCI Defined Benefit Plan, After Tax | -$4.0M | -$5.0M | — | -$7.0M | -$6.0M | -$7.0M | -$35.0M | $16.0M |
| OCI Pension Adjustments | -$4.0M | -$5.0M | — | -$7.0M | -$6.0M | -$7.0M | -$35.0M | $16.0M |
| OCI Pension Reclassification Adjustment, Pre-tax | -$4.0M | -$5.0M | — | -$7.0M | -$6.0M | -$7.0M | -$35.0M | $16.0M |
| Proceeds from disposition of property, plant and equipment/other | $5.0M | $39.0M | $44.0M | $635.0M | $706.0M | $291.0M | $1.6B | $9.0M |
| Income (Loss) from Equity Method Investments, Net of Dividends or Distributions | -$56.0M | -$181.0M | -$19.0M | $19.0M | $93.0M | -$389.0M | — | -$7.0M |
| Payments to Acquire Short-Term Investments | $1.4B | $1.1B | $44.0M | $419.0M | $42.0M | $769.0M | $19.0M | $7.0M |
| Share Repurchase Program, Excise Tax | $10.0M | $11.0M | $19.0M | $13.0M | $12.0M | $13.0M | $9.0M | $7.0M |
| OCI Unrealized Holding Gain (Loss) on Securities, Net of Tax | -$1.0M | $14.0M | — | $2.0M | $2.0M | $1.0M | $0.0 | -$6.0M |
| Unrealized Gain (Loss) on Securities | -$1.0M | $18.0M | — | $2.0M | $2.0M | $1.0M | $0.0 | -$6.0M |
| OCI Unrealized Holding Gain (Loss) on Securities, Net of Tax | -$1.0M | $14.0M | — | $2.0M | $2.0M | $1.0M | $0.0 | -$6.0M |
| Net unrealized gains (losses) on securities still held | -$1.0M | $14.0M | — | $2.0M | $2.0M | $1.0M | $0.0 | -$6.0M |
| Earnings allocated to participating share awards | $7.0M | $7.0M | $6.0M | $9.0M | $7.0M | $6.0M | $5.0M | $6.0M |
| Gain Loss On Sale Of Property Plant Equipment | -$5.0M | -$2.0M | — | $79.0M | $317.0M | $3.0M | $332.0M | $5.0M |
| Other income, net (Note 6) | $2.0M | $2.0M | -$189.0M | -$6.0M | $0.0 | $0.0 | -$14.0M | -$3.0M |
| Add - Incremental shares under stock-based compensation plans (in shares) | 2B | 2B | 2B | 2M | 1B | 2B | 1B | 1M |
| Payment for (Proceeds from) Other Investing Activity | — | — | -$25.0M | $30.0M | — | — | $2.0M | $1.0M |
| Financing — other | -$53.0M | -$68.0M | -$127.0M | -$40.0M | -$15.0M | -$20.0M | -$1.0M | $1.0M |
| Number of operating segments | — | — | — | 6.00 | — | — | — | 5.00 |
| Common Stock Dividends Per Share Declared | $0.6 | $0.6 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 |
| Common Stock Dividends Per Share | $0.6 | $0.6 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 |
| Dividends per share declared | $0.6 | $0.6 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 |
| Dividends per share declared | $0.6 | $0.6 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 |
| Common Stock Dividends Per Share Declared | $0.6 | $0.6 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 |
| Dividends declared (in dollars per share) | $0.6 | $0.6 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 |
| Common Stock Dividends Per Share Declared | $0.6 | $0.6 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 |
| Common Stock Dividends Per Share Declared | $0.6 | $0.6 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 | $0.8 |
| Effective tax rates | $0.4 | $0.4 | — | $0.4 | $0.3 | $0.4 | — | $0.4 |
| Pre-tax stock-based compensation cost | $67.0M | $67.0M | $67.0M | $84.0M | $84.0M | $84.0M | $84.0M | — |
| Asset Retirement Obligation Cash Paid To Settle | $45.5M | $45.5M | $45.5M | $64.8M | $64.8M | $64.8M | $64.8M | — |
| Asset Retirement Obligation, Liabilities Settled | $1.5M | $1.5M | $1.5M | $46.5M | $46.5M | $46.5M | $46.5M | — |
| Changes in estimated cash flows | -$35.0M | -$35.0M | -$35.0M | $37.5M | $37.5M | $37.5M | $37.5M | — |
| Additions pending the determination of proved reserves | $8.0M | $8.0M | $8.0M | $28.3M | $28.3M | $28.3M | $28.3M | — |
| Capitalized Exploratory Well Cost Sales Of Suspended Well Investment | $0.0 | $0.0 | $0.0 | $7.5M | $7.5M | $7.5M | $7.5M | — |
| Federal | $157.3M | $157.3M | $157.3M | $163.8M | $163.8M | $163.8M | $163.8M | — |
| Foreign | $812.3M | $812.3M | $812.3M | $821.8M | $821.8M | $821.8M | $821.8M | — |
| Debt repurchase, premiums paid | — | — | $283.0M | — | — | — | — | — |
| Federal | $61.8M | $61.8M | $61.8M | $134.3M | $134.3M | $134.3M | $134.3M | — |
| State | $12.3M | $12.3M | $12.3M | -$5.3M | -$5.3M | -$5.3M | -$5.3M | — |
| Deferred Tax Asset, Valuation Allowance, Charged To Expense | $102.3M | $102.3M | $102.3M | $14.8M | $14.8M | $14.8M | $14.8M | — |
| Effect of cross-border tax laws | $14.8M | $14.8M | $14.8M | $11.0M | $11.0M | $11.0M | $11.0M | — |
| Effect of cross-border tax laws | — | — | 0.4% | — | — | — | 0.4% | — |
| Nontaxable or nondeductible items | — | — | 0.1% | — | — | — | -0.2% | — |
| Changes in unrecognized tax benefits | — | — | -0.4% | — | — | — | -0.1% | — |
| Share-Based Payment Arrangement, Expense, Tax Benefit | $16.8M | $16.8M | $16.8M | $19.8M | $19.8M | $19.8M | $19.8M | — |
| Distributions of earnings from equity method investees | $570.8M | $570.8M | $570.8M | $382.8M | $382.8M | $382.8M | $382.8M | — |
| Estimated tax payable on undistributed unremitted foreign income | $65.3M | $65.3M | $65.3M | $78.5M | $78.5M | $78.5M | $78.5M | — |
| Gain (Loss), Foreign Currency Transaction, before Tax | -$9.0M | $28.0M | $13.0M | -$30.0M | $3.0M | $6.0M | — | $0.0 |
| Foreign, percent | — | — | 50.8% | — | — | — | 51.2% | — |
| United States, percent | — | — | 49.2% | — | — | — | 48.8% | — |
| Federal taxes | $74.0M | $74.0M | $74.0M | $269.3M | $269.3M | $269.3M | $269.3M | — |
| State taxes | $40.3M | $40.3M | $40.3M | $38.0M | $38.0M | $38.0M | $38.0M | — |
| Changes in unrecognized tax benefits | -$13.5M | -$13.5M | -$13.5M | -$2.8M | -$2.8M | -$2.8M | -$2.8M | — |
| Income (Loss) Before Income Taxes In Percent | — | — | 100.0% | — | — | — | 100.0% | — |
| Increase (decrease) in PP&E related to an increase (decrease) in asset retirement obligations, excluding acquisitions | $67.0M | $67.0M | $67.0M | $3.0M | $3.0M | $3.0M | $3.0M | — |
| Interest Costs Capitalized Adjustment | $62.0M | $62.0M | $62.0M | $96.0M | $96.0M | $96.0M | $96.0M | — |
| Debt | $235.3M | $235.3M | $235.3M | $294.0M | $294.0M | $294.0M | $294.0M | — |
| Fair value of contingent consideration on acquisition | $0.0 | $0.0 | $0.0 | $0.0 | $0.0 | $0.0 | $0.0 | — |
| Total other income | $12.5M | $12.5M | $12.5M | $56.8M | $56.8M | $56.8M | $56.8M | — |
| Percent amortized for net actuarial gains and losses | — | — | 10.0% | — | — | — | 10.0% | — |
| Oil and Gas, Capitalized Exploratory Well Cost, Reclassification Based on Determination of Proved Reserve | $500.0K | $500.0K | $500.0K | $0.0 | $0.0 | $0.0 | $0.0 | — |
| Revenue from contracts outside the scope of ASC Topic 606 | $1.4B | $1.4B | $1.4B | $1.8B | $1.8B | $1.8B | $1.8B | — |
| Intrinsic value of stock options exercised | $15.8M | $15.8M | $15.8M | $15.0M | $15.0M | $15.0M | $15.0M | — |
| Exercised (in shares) | — | — | $68.42 | — | — | — | $38.71 | — |
| Stock repurchase program, maximum amount | — | — | $20.0B | — | — | — | — | — |
| Acquisition of Marathon Oil | — | — | 142.9M | — | — | — | 0 | — |
| Distributed under benefit plans | — | — | 4M | — | — | — | 2.8M | — |
| Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercises in Period | — | — | 1.2M | — | — | — | 1.1M | — |
| Stock Repurchased During Period Shares | $12.3M | $12.3M | $12.3M | $13.4M | $13.4M | $13.4M | $13.4M | — |
| Stockholders' Equity, Other | — | -$1.0M | -$2.0M | $0.0 | $0.0 | -$1.0M | -$1.0M | $0.0 |
| Number of shares purchased (in shares) | — | — | 433M | — | — | — | 486M | — |
| Unrecognized tax benefits, settlements | $30.3M | $30.3M | $30.3M | $750.0K | $750.0K | $750.0K | $750.0K | — |
| Additions for tax positions of prior years | $31.8M | $31.8M | $31.8M | $3.3M | $3.3M | $3.3M | $3.3M | — |
| Asset Retirement Obligation Liabilities Incurred | $231.5M | $231.5M | $231.5M | $40.5M | $40.5M | $40.5M | $40.5M | — |
