ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - NET OF TAX EXPENSE (BENEFIT) (Details) $ in Millions	6 Months Ended
	Dec. 31, 2017 USD ($)
Hedges
Other Comprehensive Income (Loss) before Reclassifications, Tax	$ (378)	[1]
Investment Securities
Other Comprehensive Income (Loss) before Reclassifications, Tax	0	[1]
Pension and Other Retiree Benefits
Other Comprehensive Income (Loss) before Reclassifications, Tax	23	[1]
Amounts Reclassified from AOCI | Hedges
Other Comprehensive Income (Loss), Tax	0	[2]
Amounts Reclassified from AOCI | Investment Securities
Other Comprehensive Income (Loss), Tax	0	[2]
Amounts Reclassified from AOCI | Pension and Other Retiree Benefits
Other Comprehensive Income (Loss), Tax	$ 49	[2]

[1] Net of tax expense/(benefit) of $(378), $0 and $23 for gains/losses on hedges, investment securities and pension and other retiree benefit items, respectively.

[2] Net of tax expense/(benefit) of $0, $0 and $49 for gains/losses on hedges, investment securities and pension and other retiree benefit items, respectively.