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Pension and Other Postretirement Benefits - Narrative (Details) - USD ($) $ in Millions | 3 Months Ended
--- | ---
Mar. 31, 2020 | Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Restructuring charges | $ 21 | $ 12
Pension benefits | UNITED STATES |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Decrease in obligation, pension benefits |  | 75
Curtailment benefit |  | (17)
Other postretirement benefits |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Curtailment benefit | $ 0 | 58
Pension Settlement Cost |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Restructuring charges |  | $ 2

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- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit from event reducing expected years of future service of present employees or eliminating accrual of defined benefits for some or all future services of present employees. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(7) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(7) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920 + Details
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- Definition Amount of increase (decrease) in obligation for pension benefits. Includes, but is not limited to, defined benefit or defined contribution plans. Excludes other postretirement benefits. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585 + Details
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