Pension - Summary of the Projected Benefit Obligations and Assets Related to Pension Plans (Details) - Pension Benefits - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Change in benefit obligation
Benefit obligation, January 1	$ 5,600	$ 5,314
Service cost	2	2	$ 2
Interest cost	132	168	194
Actuarial losses, net	(189)	416
Benefits paid from plan assets	(304)	(285)
Benefits paid – other	(18)	(15)
Benefit obligation, December 31	5,223	5,600	5,314
Change in plan assets
Fair value of plan assets, January 1	4,623	4,441
Actual return on plan assets	522	449
Benefits paid	(304)	(285)
Contributions	5	18
Fair value of plan assets, December 31	4,846	4,623	$ 4,441
Funded status	(377)	(977)
Liability in Consolidated Balance Sheets
Accrued expenses and other liabilities	(14)	(15)
Other non-current liabilities	$ (363)	$ (962)