Employee Benefit Plans (Schedule of Changes, Net of Tax, in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Actuarial gain (loss) arising during the period	$ 96	$ (415)	$ 160
Amortization of actuarial net loss	36	28	40
Amortization of prior service credit	(23)	(23)	(25)
Total recognized in other comprehensive income (loss)	109	$ (410)	$ 175
Qualified Plan
Actuarial gain (loss) arising during the period	105
Amortization of actuarial net loss	32
Amortization of prior service credit	(14)
Total recognized in other comprehensive income (loss)	123
Non-Qualified Plan
Actuarial gain (loss) arising during the period	(10)
Amortization of actuarial net loss	4
Amortization of prior service credit	(9)
Total recognized in other comprehensive income (loss)	(15)
Postretirement Benefit Plan
Actuarial gain (loss) arising during the period	1
Amortization of actuarial net loss	0
Amortization of prior service credit	0
Total recognized in other comprehensive income (loss)	$ 1