Pension and Other Post-Employment Benefits (Details) - USD ($) $ in Millions		3 Months Ended
	Mar. 11, 2021	Mar. 31, 2022	Mar. 31, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and OPEB prior service costs amortized out of AOCI		$ 1	$ 1
Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service costs		46	49
Interest costs		68	56
Expected return on plan assets		(164)	(163)
Amortization of prior service costs (credits)		1	1
Net periodic credits, including amounts capitalized		(49)	(57)
Net periodic credits, recognized in earnings		(69)	(78)
Estimated return	7.50%
OPEB
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service costs		1	1
Interest costs		3	3
Expected return on plan assets		(10)	(10)
Amortization of prior service costs (credits)		(3)	(4)
Net periodic credits, including amounts capitalized		(9)	(10)
Net periodic credits, recognized in earnings		$ (9)	$ (10)