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, 2022	Jun. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 19	$ 23
Interest cost	67	52
Expected return on assets	(132)	(147)
Amortization of prior service costs	(2)	(2)
Net periodic pension income	$ (48)	$ (74)