ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - CHANGES IN AOCI AND RECLASSIFICATION OUT OF AOCI (Details) - USD ($) $ in Millions		3 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Jun. 30, 2019
Accumulated Other Comprehensive Income/(Loss)		$ (15,298)		$ (14,936)
OCI before Reclassifications	[1]	(439)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	[2]	73
Other Comprehensive Income (Loss), Net of Tax		(366)	$ (62)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest		(4)
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]	170
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]	0
Accumulated Other Comprehensive Income/(Loss)		6		11
OCI before Reclassifications	[1]	(3)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	[2]	(2)
Other Comprehensive Income (Loss), Net of Tax		(5)
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)		(4,019)		(4,198)
OCI before Reclassifications	[1]	104
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	[2]	75
Other Comprehensive Income (Loss), Net of Tax		179
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest		0
Reclassification from AOCI, Current Period, Tax	[2]	20
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Accumulated Other Comprehensive Income/(Loss)		(11,285)		$ (10,749)
OCI before Reclassifications	[1]	(540)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	[2]	0
Other Comprehensive Income (Loss), Net of Tax		(540)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest		$ (4)

[1] Net of tax expense/(benefit) of $0, $51 and $170 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, $20 and $0 for gains/losses on investment securities, pension and other retiree benefit items and foreign currency translation, respectively.