Employee Benefits - Narrative (Details) $ in Millions			3 Months Ended
	Feb. 24, 2022 USD ($) Retiree	Jul. 21, 2021 USD ($) Retiree	Mar. 31, 2022 USD ($)	Sep. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Non-cash pre-tax pension settlement gain			$ (10)		$ (23)
Pactiv Evergreen Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Contributions made			0
PEPP asset purchased	$ 1,260	$ 941
Projected benefit obligations	$ 1,257	$ 959
Pension benefits and annuity administration for retirees or their beneficiaries | Retiree	13,300	16,300
Non-cash pre-tax pension settlement gain			$ 10	$ 22