Long-Term Debt and Credit Agreements - Schedule of Long-term Debt (Details) - USD ($)	1 Months Ended
	Sep. 30, 2026	Sep. 30, 2024	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Total debt			$ 2,075,000,000	$ 2,075,000,000
Unamortized debt premium			90,000,000	111,000,000
Unamortized debt issuance costs			(4,000,000)	(5,000,000)
Total debt			2,161,000,000	2,181,000,000
Current portion of long-term debt			575,000,000	0
Long-term debt			$ 1,586,000,000	2,181,000,000
Senior Notes | 3.65% weighted-average private placement senior notes
Debt Instrument [Line Items]
Weighted-average interest rate			3.65%
Total debt			$ 825,000,000	825,000,000
Senior Notes | 3.65% weighted-average private placement senior notes | Scenario Forecast
Debt Instrument [Line Items]
Amount of principal repurchased	$ 250,000,000	$ 575,000,000
Senior Notes | 3.90% senior notes due May 15, 2027
Debt Instrument [Line Items]
Stated percentage			3.90%
Total debt			$ 750,000,000	750,000,000
Senior Notes | 4.375% senior notes due March 15, 2029
Debt Instrument [Line Items]
Stated percentage			4.375%
Total debt			$ 500,000,000	500,000,000
Revolving credit agreement | Revolving Credit Agreement
Debt Instrument [Line Items]
Total debt			$ 0	$ 0