EMPLOYEE BENEFIT PLANS (Retirement Income Plan's Assets Carried at Fair Value) (Details) - Retirement Income - Retirement Income - USD ($) $ in Millions	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	$ 506	$ 507	$ 485
Bond funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	459	444
International equity funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	28	36
Domestic equity funds | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	14	23
Short-term investment fund | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	3	3
Real estate fund | Fair Value Measured at Net Asset Value Per Share
Defined Benefit Plan Disclosure [Line Items]
Total assets at fair value	$ 2	$ 1