Employment Benefit Plans Change in Benefit Obligation (Details) - Pension Benefits - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Projected benefit obligation at beginning of period	$ 2,499	$ 2,295
Service cost	25	21	$ 32
Interest cost	56	70	81
Actuarial loss (gain)	(110)	262
Benefits paid	(142)	(143)
Settlements	(6)	(6)
Projected benefit obligation at end of period	2,322	2,499	$ 2,295
Component representing future salary increases	(42)	(51)
Accumulated benefit obligation at end of period	$ 2,280	$ 2,448