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Benefit Plans Contributions (Details) $ in Millions	3 Months Ended
	Dec. 31, 2020 USD ($)
Retirement Plan Disclosure
Remaining Employer Contributions	$ 225
Other Pension Plan
Retirement Plan Disclosure
Defined benefit plan contributions	75
defined benefit plan, plan assets, monthly contributions by employer	25
Other Post-retirement Benefits
Retirement Plan Disclosure
Defined benefit plan contributions	9
SERP
Retirement Plan Disclosure
Defined benefit plan contributions	5
Rebates [Member]
Retirement Plan Disclosure
Defined benefit plan contributions	1
401K [Member]
Retirement Plan Disclosure
Defined benefit plan contributions	26
Minimum | Other Pension Plan
Retirement Plan Disclosure
Defined benefit plan contributions	$ 300

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