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Benefit Plans Contributions (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2020	Mar. 31, 2020	Sep. 30, 2019
Retirement Plan Disclosure
Assets for Plan Benefits, Defined Benefit Plan	$ 6,800	$ 6,800	$ 8,000
Remaining Employer Contributions		150
Contributions to 401K		46
Other Pension Plan
Retirement Plan Disclosure
Defined benefit plan contributions		150
defined benefit plan, plan assets, monthly contributions by employer		25
Other Post-retirement Benefits
Retirement Plan Disclosure
Defined benefit plan contributions		$ 16
SERP
Retirement Plan Disclosure
Defined benefit plan contributions	5
Minimum | Other Pension Plan
Retirement Plan Disclosure
Defined benefit plan contributions	$ 300

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