Employee Benefit Plans (Net Periodic Benefit Costs) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Pension Benefits
Net periodic benefit costs [Abstract]
Service costs	$ 38	$ 52
Interest costs	118	81
Expected return on plan assets	(120)	(129)
Amortization of net actuarial (gains) losses	39	31
Amortization of prior service costs (credit)	(3)	(3)
Net periodic benefit costs (credit)	72	32
Other Postretirement Benefits
Net periodic benefit costs [Abstract]
Service costs	1	1
Interest costs	11	8
Expected return on plan assets	(13)	(13)
Amortization of net actuarial (gains) losses	(8)	(6)
Amortization of prior service costs (credit)	0	0
Net periodic benefit costs (credit)	$ (9)	$ (10)