PENSION, DEFERRED COMPENSATION AND POST-RETIREMENT BENEFIT PLANS - Fair values of the Company's pension and post-retirement plan assets by asset category (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Defined Benefit Plan Disclosure
Fair value of plan assets	$ 1,568	$ 1,440
Level 1
Defined Benefit Plan Disclosure
Fair value of plan assets	388	353
Level 2
Defined Benefit Plan Disclosure
Fair value of plan assets	825	721
Level 3
Defined Benefit Plan Disclosure
Fair value of plan assets	49	49
Assets Measured at NAV
Defined Benefit Plan Disclosure
Fair value of plan assets	306	317
Cash and cash equivalents
Defined Benefit Plan Disclosure
Fair value of plan assets	2	6
Cash and cash equivalents | Level 1
Defined Benefit Plan Disclosure
Fair value of plan assets	2	6
Short term investment funds
Defined Benefit Plan Disclosure
Fair value of plan assets	13	24
Short term investment funds | Level 2
Defined Benefit Plan Disclosure
Fair value of plan assets	7	19
Short term investment funds | Assets Measured at NAV
Defined Benefit Plan Disclosure
Fair value of plan assets	6	5
Government and agency securities
Defined Benefit Plan Disclosure
Fair value of plan assets	152	112
Government and agency securities | Level 2
Defined Benefit Plan Disclosure
Fair value of plan assets	152	112
Commingled funds
Defined Benefit Plan Disclosure
Fair value of plan assets	$ 1,259	1,149
Commingled funds | Minimum
Defined Benefit Plan Disclosure
Monthly and quarterly redemption notice periods	10 days
Commingled funds | Maximum
Defined Benefit Plan Disclosure
Monthly and quarterly redemption notice periods	30 days
Commingled funds | Level 1
Defined Benefit Plan Disclosure
Fair value of plan assets	$ 386	347
Commingled funds | Level 2
Defined Benefit Plan Disclosure
Fair value of plan assets	666	590
Commingled funds | Assets Measured at NAV
Defined Benefit Plan Disclosure
Fair value of plan assets	207	212
Insurance contracts
Defined Benefit Plan Disclosure
Fair value of plan assets	49	49
Insurance contracts | Level 3
Defined Benefit Plan Disclosure
Fair value of plan assets	49	49
Limited partnerships and hedge fund investments
Defined Benefit Plan Disclosure
Fair value of plan assets	$ 93	100
Limited partnerships and hedge fund investments | Minimum
Defined Benefit Plan Disclosure
Monthly and quarterly redemption notice periods	30 days
Limited partnerships and hedge fund investments | Maximum
Defined Benefit Plan Disclosure
Monthly and quarterly redemption notice periods	90 days
Limited partnerships and hedge fund investments | Assets Measured at NAV
Defined Benefit Plan Disclosure
Fair value of plan assets	$ 93	$ 100