Retirement Benefits - Benefit Obligations Net of Plan Assets, Balance Sheet (Details) - USD ($) $ in Millions	Jun. 30, 2022	Feb. 01, 2022	Dec. 31, 2021
Defined Contribution Plan Disclosure [Line Items]
Prepaid pension asset	$ 0		$ 1,683
Pension Benefits
Defined Contribution Plan Disclosure [Line Items]
Prepaid pension asset	0		1,683
Other current liabilities	(10)		0
Pension obligations	(682)	$ (953)	0
Non-pension postretirement benefit obligations	0		0
(Unfunded) funded status (net benefit obligation less plan assets)	(692)		1,683
OPEB
Defined Contribution Plan Disclosure [Line Items]
Prepaid pension asset	0		0
Other current liabilities	(17)		0
Pension obligations	0	$ (876)	0
Non-pension postretirement benefit obligations	(860)		(847)
(Unfunded) funded status (net benefit obligation less plan assets)	$ (877)		$ (847)