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Employee Benefit Plans - Textual (Details) - USD ($) | 1 Months Ended | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | --- | ---
Jun. 30, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017 | Dec. 31, 2017 | Dec. 01, 2017
Employee Benefit Plans (Textual) [Abstract] |  |  |  |  |  |  |  |
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax |  | $ 187,000,000 |  | $ 13,000,000 | $ 145,000,000 | $ (26,000,000) |  |
U.S. |  |  |  |  |  |  |  |
Employee Benefit Plans (Textual) [Abstract] |  |  |  |  |  |  |  |
Company contributions |  |  |  |  | 150,000,000 |  |  |
Expected company contributions |  | 160,000,000 |  |  | 160,000,000 |  |  |
U.S. | Qualified Plan [Member] |  |  |  |  |  |  |  |
Employee Benefit Plans (Textual) [Abstract] |  |  |  |  |  |  |  |
Pension settlement expense |  | 14,000,000 |  |  | 161,000,000 |  |  |
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax |  |  | $ 42,000,000 |  |  |  |  |
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate | 4.20% |  | 4.20% |  |  |  |  | 3.60%
U.S. | Qualified Plan [Member] | Prudential Benefit Obligation [Member] |  |  |  |  |  |  |  |
Employee Benefit Plans (Textual) [Abstract] |  |  |  |  |  |  |  |
Change In Defined Benefit Assets | $ 700,000,000 |  |  |  |  |  |  |
Change In Defined Benefit Obligation | $ 700,000,000 |  |  |  |  |  |  |
Int'l (Pension Benefits) [Member] |  |  |  |  |  |  |  |
Employee Benefit Plans (Textual) [Abstract] |  |  |  |  |  |  |  |
Company contributions |  |  |  |  | 130,000,000 |  |  |
Expected company contributions |  | 160,000,000 |  |  | $ 160,000,000 |  |  |
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax |  | $ (157,000,000) |  |  |  |  |  |
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate |  | 2.95% |  |  | 2.95% |  | 2.55% |
Int'l (Pension Benefits) [Member] | Qualified Plan [Member] |  |  |  |  |  |  |  |
Employee Benefit Plans (Textual) [Abstract] |  |  |  |  |  |  |  |
Reclassification of Pension Liability |  | $ 146,000,000 |  |  | $ 146,000,000 |  |  |

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- Definition Change In Defined Benefit Assets caused by funding of annuity. + References No definition available. + Details
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- Definition Change In Defined Benefit liaibilty due to purchase of annuity from Prudential. + References No definition available. + Details
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- Definition Employee benefit plans. + References No definition available. + Details
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- Definition Reclassification of Pension Liability to Other Assets. + 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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (k)(1) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
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