Pension Benefits - Schedule of Components of Net Periodic Benefit Cost (Detail) - Pension - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 10	$ 9	$ 19	$ 16
Interest cost	15	15	28	26
Expected return on assets	(21)	(20)	(39)	(36)
Amortization of prior service cost	2	2	3	4
Net periodic benefit cost	$ 6	$ 6	$ 11	$ 10