Retirement Benefit Obligations - Schedule of Amounts Recognized in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Actuarial losses (gains)	$ 527	$ 476
Prior service cost (benefit)	(14)	(16)
Net amounts recognized	513	460
Domestic
Defined Benefit Plan Disclosure [Line Items]
Actuarial losses (gains)	153	142
Prior service cost (benefit)	0	0
Net amounts recognized	153	142
Foreign Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Actuarial losses (gains)	368	333
Prior service cost (benefit)	8	9
Net amounts recognized	376	342
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Actuarial losses (gains)	6	1
Prior service cost (benefit)	(22)	(25)
Net amounts recognized	$ (16)	$ (24)