Benefit Plans (Components of Net Periodic Cost (Benefit)) (Details) - Pension Benefits - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Interest cost on projected benefit obligation	$ 62	$ 80	$ 100
Expected return on plan assets	(154)	(155)	(142)
Amortization of net actuarial (gain) loss	46	45	39
Settlement loss	1	3	0
Total net periodic pension cost (benefit)	$ (45)	$ (27)	$ (3)