Income Taxes - Schedule of Income Tax Expense Reconciled to Tax Computed at Statutory Rates (Details) - USD ($) $ in Millions	3 Months Ended					6 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2023	Sep. 30, 2023	Dec. 31, 2024		Dec. 31, 2023		Dec. 31, 2022
Expense
Federal Income Taxes								$ 957		$ 1,014		$ 1,122
State Income Taxes								147		158		120
Other								(19)		(11)		(11)
Total Income Tax Expense	$ 288	$ 262	$ 274	$ 312	$ 313	$ 625	$ 899	$ 1,085	[1]	$ 1,161	[1]	$ 1,231	[1]
Rate
Federal Income Taxes								21.00%		21.00%		21.00%
State Income Taxes								3.20%		3.30%		2.20%
Other								(0.40%)		(0.20%)		(0.20%)
Income Tax Rate								23.80%		24.10%		23.00%

[1] See Note 20, Revision of Prior Period Financial Statements