Pension and Other Benefit Plans - Pension Plan, Net Periodic Costs and Other Changes (Details) - Pension Plans, Defined Benefit - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 15	$ 19
Interest cost	79	67
Expected return on assets	(114)	(132)
Amortization of prior service credit	(2)	(2)
Net periodic pension income	$ (22)	$ (48)