ACCUMULATED OTHER COMPREHENSIVE INCOME/(LOSS) - Statement of AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2022
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 47,065	$ 46,854	$ 46,654
Other comprehensive income/(loss), before tax:
OCI before reclassifications	443	(255)
Amounts reclassified to the Consolidated Statement of Earnings	169	27
Total other comprehensive income/(loss), before tax	612	(228)
Tax effect	(295)	190
TOTAL OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAX	317	(38)	1,547
Less: OCI attributable to non-controlling interests, net of tax	(3)	(7)
Ending balance	50,559	47,065	46,854
Accumulated Other Comprehensive Income/(Loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(12,220)	(12,189)	(13,744)
Other comprehensive income/(loss), before tax:
TOTAL OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAX	320	(31)	1,555
Ending balance	(11,900)	(12,220)	(12,189)
Investment Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	13	20
Other comprehensive income/(loss), before tax:
OCI before reclassifications	(4)	(9)
Amounts reclassified to the Consolidated Statement of Earnings	0	0
Total other comprehensive income/(loss), before tax	(4)	(9)
Tax effect	1	2
TOTAL OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAX	(3)	(7)
Less: OCI attributable to non-controlling interests, net of tax	0	0
Ending balance	10	13	20
Post-retirement Benefit Plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	67	27
Other comprehensive income/(loss), before tax:
OCI before reclassifications	823	22
Amounts reclassified to the Consolidated Statement of Earnings	(47)	27
Total other comprehensive income/(loss), before tax	776	49
Tax effect	(230)	(9)
TOTAL OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAX	546	40
Less: OCI attributable to non-controlling interests, net of tax	0	0
Ending balance	613	67	27
Foreign Currency Translation
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(12,300)	(12,236)
Other comprehensive income/(loss), before tax:
OCI before reclassifications	(376)	(268)
Amounts reclassified to the Consolidated Statement of Earnings	216	0
Total other comprehensive income/(loss), before tax	(160)	(268)
Tax effect	(66)	197
TOTAL OTHER COMPREHENSIVE INCOME/(LOSS), NET OF TAX	(226)	(71)
Less: OCI attributable to non-controlling interests, net of tax	(3)	(7)
Ending balance	$ (12,522)	$ (12,300)	$ (12,236)