Employee Benefits - Net Pension Cost and Amount Recognized in OCI for All Funded and Unfunded Plans (Details) - Pension Plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 25	$ 34	$ 46
Expected return on plan assets	(28)	(38)	(48)
Amortization of losses	18	17	13
Settlement loss	9	9	18
Net pension cost (benefit)	24	22	29
Other changes in plan assets and benefit obligations recognized in OCI:
Net (gain) loss	(19)	(18)	(8)
Amortization of gains	(27)	(26)	(31)
Total recognized in comprehensive income	(46)	(44)	(39)
Total recognized in net pension cost and comprehensive income	$ (22)	$ (22)	$ (10)