Retirement Plans (Fair Value, Derivatives, Entities That Calculate Net Asset Value Per Share) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Derivatives
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, amount	$ 9	$ 71
Derivatives | Collateralized Securities
Defined Benefit Plan Disclosure [Line Items]
Derivative Asset	17	7
Derivative Holdings Gross Liabilities	(1)	7
Derivative Holdings, Net	16	0
Derivatives | Credit Default Swap
Defined Benefit Plan Disclosure [Line Items]
Derivative Asset	3	2
Derivative Holdings Gross Liabilities	0	0
Derivative Holdings, Net	3	2
Derivatives | Interest Rate Swap
Defined Benefit Plan Disclosure [Line Items]
Derivative Asset	7	4
Derivative Holdings Gross Liabilities	0	0
Derivative Holdings, Net	7	4
Derivatives | Equity Swap
Defined Benefit Plan Disclosure [Line Items]
Derivative Asset	0	65
Derivative Holdings Gross Liabilities	(17)	0
Derivative Holdings, Net	(17)	65
Derivatives | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets, amount	9	71
Derivative Financial Instruments, Liabilities
Defined Benefit Plan Disclosure [Line Items]
Derivative Holdings Gross Liabilities	(18)	(7)
Derivative Financial Instruments, Assets
Defined Benefit Plan Disclosure [Line Items]
Derivative Asset	$ 27	$ 78