ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - CHANGES IN AOCI AND RECLASSIFICATION OUT OF AOCI (Details) - USD ($) $ in Millions		3 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023
Accumulated Other Comprehensive Income/(Loss)		$ (12,583)		$ (12,220)
OCI before Reclassifications	[1]	(367)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	[2]	1
Other Comprehensive Income (Loss), Net of Tax		(366)	$ (627)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest		(2)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Including Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income/(Loss)		11		13
OCI before Reclassifications	[1]	(1)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	[2]	0
Other Comprehensive Income (Loss), Net of Tax		(1)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest		0
Other Comprehensive Income (Loss) before Reclassifications, Tax	[1]	0
Reclassification from AOCI, Current Period, Tax	[2]	0
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Including Portion Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income/(Loss)		112		67
OCI before Reclassifications	[1]	44
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	[2]	1
Other Comprehensive Income (Loss), Net of Tax		45
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest		0
Other Comprehensive Income (Loss) before Reclassifications, Tax	[1]	22
Reclassification from AOCI, Current Period, Tax	[2]	(2)
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income/(Loss)		(12,707)		$ (12,300)
OCI before Reclassifications	[1]	(409)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	[2]	0
Other Comprehensive Income (Loss), Net of Tax		(409)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest		(2)
Other Comprehensive Income (Loss) before Reclassifications, Tax	[1]	148
Reclassification from AOCI, Current Period, Tax	[2]	$ 0

[1] Net of tax (benefit)/expense of $0, $22 and $148 for gains/losses on investment securities, postretirement benefit plans and foreign currency translation, respectively. Income tax effects within foreign currency translation include impacts from items such as net investment hedge transactions.

[2] Net of tax (benefit)/expense of $0, $(2) and $0 for gains/losses on investment securities, postretirement benefit plans and foreign currency translation, respectively.