Basis of Presentation - Schedule of Effect of Change in Estimate (Details) - USD ($) $ in Millions	6 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Sep. 30, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Change in Accounting Estimate [Line Items]
Net change in revolving credit facility and short-term debt	$ 0	$ (393)	$ (393)	$ (396)	$ 268	$ 39
Proceeds from short-term debt	124	120	127	129	45	15
Payments of short-term debt	(44)	(38)	(96)	(131)	(45)	(42)
Net cash provided by financing activities	$ (70)	101	35	116	(25)	(2,944)
As Previously Reported
Change in Accounting Estimate [Line Items]
Net change in revolving credit facility and short-term debt		(311)	(362)	(398)	268	12
Proceeds from short-term debt		0	0	0	0	0
Payments of short-term debt		0	0	0	0	0
Net cash provided by financing activities		101	35	116	(25)	(2,944)
Adjustments
Change in Accounting Estimate [Line Items]
Net change in revolving credit facility and short-term debt		(82)	(31)	2	0	27
Proceeds from short-term debt		120	127	129	45	15
Payments of short-term debt		(38)	(96)	(131)	(45)	(42)
Net cash provided by financing activities		$ 0	$ 0	$ 0	$ 0	$ 0