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Benefit Plans Contributions (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Jun. 30, 2021 | Jun. 30, 2021
Retirement Plan Disclosure |  |
Remaining Employer Contributions |  | $ 75
Other Pension Plan |  |
Retirement Plan Disclosure |  |
Defined benefit plan contributions |  | 225
defined benefit plan, plan assets, monthly contributions by employer |  | 25
Other Post-retirement Benefits |  |
Retirement Plan Disclosure |  |
Defined benefit plan contributions |  | 20
SERP |  |
Retirement Plan Disclosure |  |
Defined benefit plan contributions | $ 6 |
Rebates [Member] |  |
Retirement Plan Disclosure |  |
Defined benefit plan contributions |  | 2
401K [Member] |  |
Retirement Plan Disclosure |  |
Defined benefit plan contributions |  | $ 70
Minimum | Other Pension Plan |  |
Retirement Plan Disclosure |  |
Defined benefit plan contributions | $ 300 |

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