Benefit Plans - Summary of the Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2025		Jun. 30, 2024		Jun. 30, 2025	Jun. 30, 2024
Net periodic pension cost:
Service cost(1)	$ 69	[1]	$ 84	[1]	$ 137	$ 180
Interest cost	114		112		228	220
Estimated return on plan assets	(242)		(238)		(485)	(482)
Net amortization and other	0		0		0	1
Net periodic (benefit) cost	$ (59)		(42)		$ (120)	(81)
IH
Net periodic pension cost:
Service cost(1)			$ 2			$ 10

[1] Includes $2 million and $10 million for the three and six months ended June 30, 2024, respectively, of service cost reported in net income from discontinued operations for the qualified defined benefit pension plan for employees of TIH.