Employee Benefits - Additional Information (Detail) $ in Millions			3 Months Ended			6 Months Ended		10 Months Ended
	Mar. 06, 2024 retiree	Feb. 29, 2024 USD ($) agreement	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Mar. 31, 2025 employee
Defined Benefit Plan Disclosure [Line Items]
Number of pension authorization commitment agreements | agreement		2
Liability, defined benefit plan		$ 5,800
Restructuring and related cost, number of positions eliminated | employee								4,800
Post employment benefits liability			$ 389			$ 389
Employee Severance
Defined Benefit Plan Disclosure [Line Items]
Amount paid in severance benefits over the period			201			607
Other Postemployment Benefits
Defined Benefit Plan Disclosure [Line Items]
Amount paid in severance benefits over the period						96
Pension
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, benefit obligation, actuarial gain (loss) from pension annuitization		$ 200			$ 200
Number of retirees receiving benefit payments from pension plan | retiree	56,000
Defined benefit plan, plan assets, increase (decrease) for assets transferred to (from) plan						5,600
Employer discretionary contribution amount			563			563	$ 365
Remeasurement gain (loss), net			$ (45)	$ (136)	73	$ (45)	$ (63)
Defined benefit plan, benefit obligation, actuarial loss from settlements					127
Charge due to difference between estimated and actual return on assets				245	613
Defined benefit plan, benefit obligation, actuarial gain (loss) from assumptions used calculating benefit obligation, discount rate				$ 109	$ 486