PENSION, DEFERRED COMPENSATION AND POST-RETIREMENT BENEFIT PLANS - Projected and Accumulated Benefit Obligation and Fair Value of Plan Assets (Details) - USD ($) $ in Millions	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Defined Benefit Plan Disclosure
Fair value of plan assets	$ 1,568	$ 1,440
Pension Plans | Retirement Growth Account
Defined Benefit Plan Disclosure
Projected benefit obligation	940	830
Accumulated benefit obligation	887	784
Fair value of plan assets	930	832
Pension Plans | Pension Plans Restoration
Defined Benefit Plan Disclosure
Projected benefit obligation	142	136
Accumulated benefit obligation	124	120
Fair value of plan assets	0	0
Pension Plans | International
Defined Benefit Plan Disclosure
Projected benefit obligation	636	631	$ 588
Accumulated benefit obligation	576	569
Fair value of plan assets	611	577	$ 561
Defined benefit plans with obligations in excess of plan assets:
Pension plans with projected benefit obligations in excess of the plans' assets, aggregate projected benefit obligations	330	319
Pension plans with projected benefit obligations in excess of the plans' assets, aggregate fair value of plan assets	178	162
Defined benefit plans with accumulated benefit obligations in excess of plan assets:
Pension plans with accumulated benefit obligations in excess of the plans' assets, aggregate accumulated benefit obligations	246	241
Pension plans with accumulated benefit obligations in excess of the plans' assets, aggregate fair value of plan assets	$ 128	$ 116