Financing (Details) - USD ($)	Mar. 31, 2025	Dec. 31, 2024
Unsecured Debt
Debt Instrument [Line Items]
Weighted-average interest rates	4.95%	4.95%
Unsecured Debt | Total Notes And Debentures
Debt Instrument [Line Items]
Total notes and debentures	$ 3,300,000,000	$ 3,300,000,000
Line of Credit
Line of Credit Facility [Abstract]
Line of credit, outstanding borrowings	0
Available borrowing capacity	1,000,000,000.0
Line of Credit | Amendment No. 3 Credit Agreement - 2021
Line of Credit Facility [Abstract]
Maximum borrowing capacity	1,000,000,000.0
Line of Credit | Amendment No. 5 Credit Agreement - 2023
Line of Credit Facility [Abstract]
Maximum borrowing capacity	$ 912,200,000