Long-Term Debt and Credit Agreements - Narrative (Details) - USD ($)	Sep. 12, 2024	Sep. 30, 2024	Sep. 11, 2024	Mar. 13, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Debt issuance costs		$ 7,000,000			$ 4,000,000
Total debt		2,000,000,000			2,075,000,000
Unamortized discount		1,000,000			0
Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Total debt		0			0
Remaining borrowing capacity		$ 2,000,000,000.0
Line of Credit | Revolving Credit Facility | JPMorgan Chase Bank, N.A
Debt Instrument [Line Items]
Maximum borrowing capacity on line of credit	$ 2,000,000,000		$ 1,500,000,000
Debt issuance costs	$ 4,000,000
Agreement extended period	1 year
Lenders holding percent	50.00%
Minimum required asset coverage ratio	3.0
Other debt outstanding	$ 75,000,000
Total capitalization	65.00%
Line of Credit | Revolving Credit Facility | JPMorgan Chase Bank, N.A | Minimum
Debt Instrument [Line Items]
Commitment fee on unused credit	0.10%
Line of Credit | Revolving Credit Facility | JPMorgan Chase Bank, N.A | Maximum
Debt Instrument [Line Items]
Commitment fee on unused credit	0.25%
Line of Credit | Revolving Credit Facility | JPMorgan Chase Bank, N.A | Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Basis spread on variable rate	0.10%
Line of Credit | Revolving Credit Facility | JPMorgan Chase Bank, N.A | Secured Overnight Financing Rate (SOFR) | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%
Line of Credit | Revolving Credit Facility | JPMorgan Chase Bank, N.A | Secured Overnight Financing Rate (SOFR) | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
Line of Credit | Revolving Credit Facility | JPMorgan Chase Bank, N.A | Base Rate | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.00%
Line of Credit | Revolving Credit Facility | JPMorgan Chase Bank, N.A | Base Rate | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	0.75%
3.65% weighted-average private placement senior notes | Senior Notes
Debt Instrument [Line Items]
Weighted average interest rate		3.65%
Total debt		$ 250,000,000			825,000,000
5.60% Senior Notes Due March 15, 2034 | Senior Notes
Debt Instrument [Line Items]
Debt issuance costs				$ 5,000,000
Total debt		$ 500,000,000		$ 500,000,000	$ 0
Stated percentage		5.60%		5.60%
Unamortized discount				$ 1,000,000