ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Statement of AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2023
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 50,559	$ 47,065	$ 46,854
Other comprehensive income/(loss), before tax:
OCI before reclassifications	(1,769)	443
Amounts reclassified to the Consolidated Statement of Earnings	671	169
Total other comprehensive income/(loss), before tax	(1,098)	612
Tax effect	850	(295)
TOTAL OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAX	(248)	317	(38)
Less: OCI attributable to non-controlling interests, net of tax	(4)	(3)
Ending balance	52,284	50,559	47,065
Total AOCI
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(11,900)	(12,220)
Other comprehensive income/(loss), before tax:
Ending balance	(12,143)	(11,900)	(12,220)
Investment Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	10	13
Other comprehensive income/(loss), before tax:
OCI before reclassifications	(1)	(4)
Amounts reclassified to the Consolidated Statement of Earnings	0	0
Total other comprehensive income/(loss), before tax	(1)	(4)
Tax effect	1	1
TOTAL OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAX	0	(3)
Less: OCI attributable to non-controlling interests, net of tax	0	0
Ending balance	9	10	13
Post-retirement Benefit Plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	613	67
Other comprehensive income/(loss), before tax:
OCI before reclassifications	(1,717)	823
Amounts reclassified to the Consolidated Statement of Earnings	(81)	(47)
Total other comprehensive income/(loss), before tax	(1,798)	776
Tax effect	407	(230)
TOTAL OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAX	(1,390)	546
Less: OCI attributable to non-controlling interests, net of tax	0	0
Ending balance	(777)	613	67
Foreign Currency Translation
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(12,522)	(12,300)
Other comprehensive income/(loss), before tax:
OCI before reclassifications	(51)	(376)
Amounts reclassified to the Consolidated Statement of Earnings	752	216
Total other comprehensive income/(loss), before tax	701	(160)
Tax effect	442	(66)
TOTAL OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAX	1,143	(226)
Less: OCI attributable to non-controlling interests, net of tax	(4)	(3)
Ending balance	$ (11,375)	$ (12,522)	$ (12,300)