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Pensions And Other Postretirement Benefits Components of Expense and Assumptions (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Weighted-average assumptions used to determine net expense(b) |  |  |  |
Amounts to be amortized from accumulated other comprehensive loss into net periodic benefit cost, next fiscal year |  | $ 166 |  |
Other Postretirement Benefits Plan [Member] |  |  |  |
Components of expense |  |  |  |
Service cost |  | 19 | $ 18 | $ 24
Interest cost |  | 202 | 201 | 238
Expected return on plan assets |  | 0 | 0 | 0
Amortization of net actuarial (gains) losses |  | 23 | 19 | 37
Curtailments, settlements and other |  | (5) | (13) | (14)
Net periodic pension and OPEB (income) expense |  | $ 239 | $ 225 | $ 285
Weighted-average assumptions used to determine benefit obligations(b) |  |  |  |
Discount rate |  | 3.52% | 3.93% | 4.13%
Weighted-average assumptions used to determine net expense(b) |  |  |  |
Discount rate |  | 3.39% | 3.49% | 3.83%
U.S. [Member] | Pension Plan [Member] |  |  |  |
Components of expense |  |  |  |
Service cost |  | $ 315 | $ 381 | $ 406
Service cost |  | 203 | 220 |
Interest cost |  | 2,145 | 2,212 | 2,754
Expected return on plan assets |  | (3,677) | (3,778) | (3,896)
Amortization of net actuarial (gains) losses |  | (6) | (25) | 8
Curtailments, settlements and other |  | (37) | (4) | (4)
Net periodic pension and OPEB (income) expense |  | $ (1,260) | $ (1,214) | $ (732)
Weighted-average assumptions used to determine benefit obligations(b) |  |  |  |
Discount rate |  | 3.53% | 3.92% | 4.06%
Weighted-average assumptions used to determine net expense(b) |  |  |  |
Discount rate |  | 3.35% | 3.36% | 3.73%
Expected rate of return on plan assets |  | 6.23% | 6.33% | 6.38%
U.S. [Member] | Pension Plan [Member] | Forecast [Member] |  |  |  |
Weighted-average assumptions used to determine net expense(b) |  |  |  |
Expected rate of return on plan assets | 6.60% |  |  |
Non-U.S. [Member] | Pension Plan [Member] |  |  |  |
Components of expense |  |  |  |
Service cost |  | $ 199 | $ 273 | $ 306
Service cost |  | 180 | 255 |
Interest cost |  | 473 | 527 | 689
Expected return on plan assets |  | (750) | (733) | (794)
Amortization of net actuarial (gains) losses |  | 157 | 137 | 188
Curtailments, settlements and other |  | 8 | 16 | 141
Net periodic pension and OPEB (income) expense |  | $ 87 | $ 220 | $ 530
Weighted-average assumptions used to determine benefit obligations(b) |  |  |  |
Discount rate |  | 2.66% | 2.88% | 3.36%
Weighted-average assumptions used to determine net expense(b) |  |  |  |
Discount rate |  | 2.94% | 3.14% | 3.30%
Expected rate of return on plan assets |  | 5.82% | 6.07% | 6.32%

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- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit 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 (h)(4) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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