Nonoperating Income (Expense) (Schedule of Nonoperating Income (Expense)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Other Income and Expenses [Abstract]
Other components of net periodic benefit costs	$ 1	$ 7	$ 44
Realized investment gains (losses)	156	89	123
Unrealized investment gains (losses)	(213)	(271)	(394)
Total investment gains (losses)	(57)	(182)	(271)
Total other income (expense), net	$ (56)	$ (175)	$ (227)