ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - CHANGES IN AOCI AND RECLASSIFICATION OUT OF AOCI (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Jun. 30, 2019
Accumulated Other Comprehensive Income/(Loss)		$ (15,916)		$ (15,916)		$ (14,936)
OCI before Reclassifications	[1]			(1,218)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	[2]			221
Other Comprehensive Income (Loss), Net of Tax		(985)	$ 191	(997)	$ 107
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest				(17)
Accumulated Other Comprehensive Income (Loss), Derivative Qualifying as Hedge, Excluded Component, Including Portion Attributable to Noncontrolling Interest [Member]
Other Comprehensive Income (Loss) before Reclassifications, Tax	[1]			141
Reclassification from AOCI, Current Period, Tax	[2]			0
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Including Noncontrolling Interest [Member]
Other Comprehensive Income (Loss) before Reclassifications, Tax	[1]			(2)
Accumulated Other Comprehensive Income/(Loss)		(1)		(1)		11
OCI before Reclassifications	[1]			(10)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	[2]			(2)
Other Comprehensive Income (Loss), Net of Tax				(12)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest				0
Reclassification from AOCI, Current Period, Tax	[2]			0
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Including Portion Attributable to Noncontrolling Interest
Other Comprehensive Income (Loss) before Reclassifications, Tax	[1]			51
Accumulated Other Comprehensive Income/(Loss)		(3,871)		(3,871)		(4,198)
OCI before Reclassifications	[1]			104
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	[2]			223
Other Comprehensive Income (Loss), Net of Tax				327
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest				0
Reclassification from AOCI, Current Period, Tax	[2]			66
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income/(Loss)		$ (12,044)		(12,044)		$ (10,749)
OCI before Reclassifications	[1]			(1,312)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	[2]			0
Other Comprehensive Income (Loss), Net of Tax				(1,312)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest				$ (17)

[1] Net of tax expense/(benefit) of $(2), $51 and $141 for gains/losses on investment securities, pension and other retiree benefit items and foreign currency translation, respectively.

[2] Net of tax expense/(benefit) of $0, $66 and $0 for gains/losses on investment securities, pension and other retiree benefit items and foreign currency translation, respectively.