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Pension Benefit Obligations - Target Allocation and Plan Assets (Details) | Sep. 30, 2019 | Sep. 30, 2018
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United States |  |
Components of net periodic benefit cost: |  |
Target allocations (as a percent) | 100.00% |
Plan assets (as a percent) | 100.00% | 100.00%
United States | Equity securities |  |
Components of net periodic benefit cost: |  |
Target allocations (as a percent) | 45.00% |
Plan assets (as a percent) | 45.00% | 40.00%
United States | Debt |  |
Components of net periodic benefit cost: |  |
Target allocations (as a percent) | 42.00% |
Plan assets (as a percent) | 45.00% | 50.00%
United States | Cash and cash equivalents |  |
Components of net periodic benefit cost: |  |
Target allocations (as a percent) | 3.00% |
Plan assets (as a percent) | 1.00% | 1.00%
United States | Property And Other |  |
Components of net periodic benefit cost: |  |
Target allocations (as a percent) | 10.00% |
Plan assets (as a percent) | 9.00% | 9.00%
International |  |
Components of net periodic benefit cost: |  |
Target allocations (as a percent) | 100.00% |
Plan assets (as a percent) | 100.00% | 100.00%
International | Equity securities |  |
Components of net periodic benefit cost: |  |
Target allocations (as a percent) | 37.00% |
Plan assets (as a percent) | 36.00% | 38.00%
International | Debt |  |
Components of net periodic benefit cost: |  |
Target allocations (as a percent) | 36.00% |
Plan assets (as a percent) | 31.00% | 36.00%
International | Cash and cash equivalents |  |
Components of net periodic benefit cost: |  |
Target allocations (as a percent) | 6.00% |
Plan assets (as a percent) | 3.00% | 7.00%
International | Property And Other |  |
Components of net periodic benefit cost: |  |
Target allocations (as a percent) | 21.00% |
Plan assets (as a percent) | 30.00% | 19.00%

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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/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(i) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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