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Pension and Postretirement Benefit Plans - US Pension Weighted Averages and Expected Returns Information (Details) - Funded - USD ($) $ in Millions | 1 Months Ended | 12 Months Ended
--- | --- | ---
Aug. 31, 2015 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Qualified and Non-qualified Pension Benefits |  |  |  |
Benefit Plan Information |  |  |  |
Company contributions |  | $ 964 | $ 380 |
Qualified and Non-qualified Pension Benefits | Maximum |  |  |  |
Asset Allocation assumption |  |  |  |
Estimated pension contributions for next fiscal year |  | 500 |  |
Qualified and Non-qualified Pension Benefits | Minimum |  |  |  |
Asset Allocation assumption |  |  |  |
Estimated pension contributions for next fiscal year |  | 300 |  |
Postretirement Benefits |  |  |  |
Benefit Plan Information |  |  |  |
Company contributions |  | 3 | $ 3 |
Amounts expected to be amortized from accumulated other comprehensive income into net periodic benefit costs over next fiscal year |  |  |  |
Amortization of prior service cost (benefit) |  | (40) |  |
Amortization of net actuarial (gain) loss |  | 62 |  |
Total amortization expected over the next fiscal year |  | $ 22 |  |
Weighted-average assumptions used to determine benefit obligations |  |  |  |
Discount rate |  | 3.79% | 4.26% | 4.48%
Percentage increase (decrease) in discount rate obligation from the prior year |  | (0.47%) |  |
Weighted-average assumptions used to determine net cost for years ended |  |  |  |
Discount rate - service cost |  | 4.50% | 4.70% | 4.07%
Discount rate - interest cost |  | 3.80% | 3.80% | 4.07%
Expected return on assets |  | 6.48% | 6.91% | 6.91%
United States |  |  |  |
Weighted-average assumptions used to determine benefit obligations |  |  |  |
Original percentage medical inflation indexation by company in year | 3.00% |  |  |
Revised percentage medical inflation indexation by company in year | 1.50% |  |  |
United States | Qualified and Non-qualified Pension Benefits |  |  |  |
Benefit Plan Information |  |  |  |
Company contributions |  | $ 852 | $ 259 |
Amounts expected to be amortized from accumulated other comprehensive income into net periodic benefit costs over next fiscal year |  |  |  |
Amortization of prior service cost (benefit) |  | (23) |  |
Amortization of net actuarial (gain) loss |  | 503 |  |
Total amortization expected over the next fiscal year |  | $ 480 |  |
Weighted-average assumptions used to determine benefit obligations |  |  |  |
Discount rate |  | 3.68% | 4.21% | 4.47%
Compensation rate increase |  | 4.10% | 4.10% | 4.10%
Percentage increase (decrease) in discount rate obligation from the prior year |  | (0.53%) |  |
Weighted-average assumptions used to determine net cost for years ended |  |  |  |
Discount rate - service cost |  | 4.42% | 4.70% | 4.10%
Discount rate - interest cost |  | 3.61% | 3.73% | 4.10%
Expected return on assets |  | 7.25% | 7.50% | 7.75%
Compensation rate increase |  | 4.10% | 4.10% | 4.10%
International Qualified and Non-qualified Pension Benefits | Qualified and Non-qualified Pension Benefits |  |  |  |
Benefit Plan Information |  |  |  |
Company contributions |  | $ 112 | $ 121 |
Amounts expected to be amortized from accumulated other comprehensive income into net periodic benefit costs over next fiscal year |  |  |  |
Amortization of prior service cost (benefit) |  | (13) |  |
Amortization of net actuarial (gain) loss |  | 116 |  |
Total amortization expected over the next fiscal year |  | $ 103 |  |
Weighted-average assumptions used to determine benefit obligations |  |  |  |
Discount rate |  | 2.41% | 2.54% | 3.12%
Compensation rate increase |  | 2.89% | 2.90% | 2.90%
Weighted-average assumptions used to determine net cost for years ended |  |  |  |
Discount rate - service cost |  | 2.32% | 2.84% | 3.11%
Discount rate - interest cost |  | 2.25% | 2.72% | 3.11%
Expected return on assets |  | 5.16% | 5.77% | 5.90%
Compensation rate increase |  | 2.90% | 2.90% | 3.33%
Qualified | United States | Qualified and Non-qualified Pension Benefits |  |  |  |
Asset Allocation assumption |  |  |  |
Rate of return on plan assets |  | 12.40% | 5.80% | 0.70%
Average annual actual return on plan assets over the past 10 years |  | 7.00% |  |
Number years of used in the calculation of one average annual actual return on plan assets |  | 10 years |  |
Average annual actual return on plan assets over the past 25 years |  | 9.40% |  |
Number years of used in the calculation of a second average annual actual return on plan assets |  | 25 years |  |
Company's assumption for the expected return on plan assets |  |  |  |
Expected return on assets in next fiscal year |  | 7.25% |  |
Qualified | United States | Qualified and Non-qualified Pension Benefits | Primary U.S. Qualified Pension Plan |  |  |  |
Company's assumption for the expected return on plan assets |  |  |  |
Expected return on assets in next fiscal year |  | 7.25% |  |
Qualified | United States | Qualified and Non-qualified Pension Benefits | Equities |  |  |  |
Asset Allocation assumption |  |  |  |
Asset allocation assumption for next fiscal year |  | 25.00% |  |
Qualified | United States | Qualified and Non-qualified Pension Benefits | Private equity |  |  |  |
Asset Allocation assumption |  |  |  |
Asset allocation assumption for next fiscal year |  | 16.00% |  |
Qualified | United States | Qualified and Non-qualified Pension Benefits | Fixed income |  |  |  |
Asset Allocation assumption |  |  |  |
Asset allocation assumption for next fiscal year |  | 41.00% |  |
Qualified | United States | Qualified and Non-qualified Pension Benefits | Absolute return |  |  |  |
Asset Allocation assumption |  |  |  |
Asset allocation assumption for next fiscal year |  | 18.00% |  |

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- Definition This element represents the interest rate used to adjust for time value of money for interest costs. + References No definition available. + Details
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- Definition The number years of used in the calculation of one average annual actual return on plan assets. + References No definition available. + Details
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- Definition The number years of used in the calculation of a second average annual actual return on plan assets. + References No definition available. + Details
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- Definition The average annual actual return on plan assets over the past ten years, percentage. + References No definition available. + Details
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- Definition The average annual actual return on plan assets over the past twenty-five years, percentage. + References No definition available. + Details
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- Definition This element represents the percentage change in assumed discount rate from the prior year used in calculating the benefit obligation. + References No definition available. + Details
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- Definition The original percentage that the Company would credit the Retiree Medical Saving Account and the Medicare Health Reimbursement Arrangement as an inflation indexation. + References No definition available. + Details
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- Definition The revised percentage that the Company would credit the Retiree Medical Savings Account and the Medicare Health Reimbursement arrangement as an inflation indexation. + References No definition available. + Details
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- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine benefit obligation of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Weighted average rate increase of compensation, used to determine benefit obligation of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(2) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(3) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Weighted average rate of compensation increase used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(2) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Amount of contribution received by defined benefit plan from employer which increases plan assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(5)(ii) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2709-114920 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(5)(iv)(01) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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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. + Details
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- Definition Amount of cost (credit) included in accumulated other comprehensive (income) loss expected to be recognized in net periodic benefit cost (credit) for fiscal year following most recent annual statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (s) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Amount included in accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan expected to be recognized in net periodic benefit (cost) credit for fiscal year following most recent annual statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (s) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Amount included in accumulated other comprehensive (income) loss for prior service cost (credit) expected to be recognized in net periodic benefit cost (credit) for fiscal year following most recent annual statement of financial position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (s) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Amount of contributions expected to be received by defined benefit plan from employer in next fiscal year following latest fiscal year. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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- Definition Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(5)(i) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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