EMPLOYEE BENEFIT PLANS (Retirement Income Plan's Assets Carried at Fair Value) (Details) - Retirement Income Plans [Member] - Other Postretirement Benefit Plan [Member] - USD ($) $ in Millions	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	$ 434	$ 423	$ 409
Fair Value, Measurements, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value, excluding net asset value investments	2	2
Common collective trusts measured at net asset value	432	421
Total assets at fair value	434	423
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value, excluding net asset value investments	2	2
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value, excluding net asset value investments	0	0
Fair Value, Measurements, Recurring [Member] | Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	2	2
Fair Value, Measurements, Recurring [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	2	2
Fair Value, Measurements, Recurring [Member] | Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Bond Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Common collective trusts measured at net asset value	310	307
Fair Value, Measurements, Recurring [Member] | International Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Common collective trusts measured at net asset value	64	56
Fair Value, Measurements, Recurring [Member] | Domestic Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Common collective trusts measured at net asset value	46	44
Fair Value, Measurements, Recurring [Member] | Real Estate Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Common collective trusts measured at net asset value	$ 12	$ 14