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Pension Benefit Obligations - Target Allocation and Plan Assets (Details) | Sep. 30, 2018 | Sep. 30, 2017
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United States |  |
Target Allocations by Asset Category |  |
Target Allocations by Asset Category (as a percent) | 100.00% |
Percentage of Plan Assets by Category |  |
Plan Assets by Asset Category (as a percent) | 100.00% | 100.00%
United States | Equity securities |  |
Target Allocations by Asset Category |  |
Target Allocations by Asset Category (as a percent) | 40.00% |
Percentage of Plan Assets by Category |  |
Plan Assets by Asset Category (as a percent) | 40.00% | 43.00%
United States | Debt |  |
Target Allocations by Asset Category |  |
Target Allocations by Asset Category (as a percent) | 51.00% |
Percentage of Plan Assets by Category |  |
Plan Assets by Asset Category (as a percent) | 50.00% | 47.00%
United States | Cash and cash equivalents |  |
Target Allocations by Asset Category |  |
Target Allocations by Asset Category (as a percent) | 1.00% |
Percentage of Plan Assets by Category |  |
Plan Assets by Asset Category (as a percent) | 1.00% | 1.00%
United States | Property And Other |  |
Target Allocations by Asset Category |  |
Target Allocations by Asset Category (as a percent) | 8.00% |
Percentage of Plan Assets by Category |  |
Plan Assets by Asset Category (as a percent) | 9.00% | 9.00%
Foreign Pension Plan, Defined Benefit |  |
Target Allocations by Asset Category |  |
Target Allocations by Asset Category (as a percent) | 100.00% |
Percentage of Plan Assets by Category |  |
Plan Assets by Asset Category (as a percent) | 100.00% | 100.00%
Foreign Pension Plan, Defined Benefit | Equity securities |  |
Target Allocations by Asset Category |  |
Target Allocations by Asset Category (as a percent) | 25.00% |
Percentage of Plan Assets by Category |  |
Plan Assets by Asset Category (as a percent) | 38.00% | 27.00%
Foreign Pension Plan, Defined Benefit | Debt |  |
Target Allocations by Asset Category |  |
Target Allocations by Asset Category (as a percent) | 35.00% |
Percentage of Plan Assets by Category |  |
Plan Assets by Asset Category (as a percent) | 36.00% | 38.00%
Foreign Pension Plan, Defined Benefit | Cash and cash equivalents |  |
Target Allocations by Asset Category |  |
Target Allocations by Asset Category (as a percent) | 10.00% |
Percentage of Plan Assets by Category |  |
Plan Assets by Asset Category (as a percent) | 7.00% | 2.00%
Foreign Pension Plan, Defined Benefit | Property And Other |  |
Target Allocations by Asset Category |  |
Target Allocations by Asset Category (as a percent) | 30.00% |
Percentage of Plan Assets by Category |  |
Plan Assets by Asset Category (as a percent) | 19.00% | 33.00%

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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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- Definition Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e2446-114920 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920 + Details
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