PENSION, DEFERRED COMPENSATION AND POST-RETIREMENT BENEFIT PLANS - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Pension Plans | U.S.
Components of net periodic benefit cost:
Service cost	$ 39	$ 38	$ 37
Interest cost	35	37	33
Expected return on assets	(53)	(55)	(53)
Amortization of:
Actuarial loss	15	11	14
Prior service cost	0	1	0
Settlements	0	0	0
Special termination benefits	0	0	0
Net periodic benefit cost	$ 36	$ 32	$ 31
Weighted-average assumptions used to determine net periodic benefit cost for the year ended June 30:
Expected return on assets (as a percent)	6.75%	6.75%	7.00%
Pension Plans | U.S. | Minimum
Weighted-average assumptions used to determine benefit obligations at June 30:
Discount rate (as a percent)	2.50%	3.40%	4.10%
Rate of compensation increase (as a percent)	2.50%	2.50%	2.50%
Weighted-average assumptions used to determine net periodic benefit cost for the year ended June 30:
Discount rate (as a percent)	3.40%	4.10%	3.40%
Rate of compensation increase (as a percent)	2.50%	2.50%	3.00%
Pension Plans | U.S. | Maximum
Weighted-average assumptions used to determine benefit obligations at June 30:
Discount rate (as a percent)	3.00%	3.80%	4.30%
Rate of compensation increase (as a percent)	8.00%	8.00%	8.00%
Weighted-average assumptions used to determine net periodic benefit cost for the year ended June 30:
Discount rate (as a percent)	3.80%	4.30%	3.90%
Rate of compensation increase (as a percent)	8.00%	8.00%	7.00%
Pension Plans | International
Components of net periodic benefit cost:
Service cost	$ 36	$ 30	$ 30
Interest cost	11	13	13
Expected return on assets	(14)	(14)	(15)
Amortization of:
Actuarial loss	6	3	5
Prior service cost	0	(1)	0
Settlements	0	1	0
Special termination benefits	0	0	1
Net periodic benefit cost	$ 39	$ 32	$ 34
Pension Plans | International | Minimum
Weighted-average assumptions used to determine benefit obligations at June 30:
Discount rate (as a percent)	0.50%	0.25%	0.50%
Rate of compensation increase (as a percent)	1.00%	1.00%	1.00%
Weighted-average assumptions used to determine net periodic benefit cost for the year ended June 30:
Discount rate (as a percent)	0.25%	0.50%	0.50%
Expected return on assets (as a percent)	1.50%	1.50%	1.75%
Rate of compensation increase (as a percent)	1.00%	1.00%	1.00%
Pension Plans | International | Maximum
Weighted-average assumptions used to determine benefit obligations at June 30:
Discount rate (as a percent)	7.00%	8.50%	7.50%
Rate of compensation increase (as a percent)	5.50%	5.50%	5.50%
Weighted-average assumptions used to determine net periodic benefit cost for the year ended June 30:
Discount rate (as a percent)	8.50%	7.50%	6.75%
Expected return on assets (as a percent)	8.50%	7.50%	6.75%
Rate of compensation increase (as a percent)	5.50%	5.50%	5.50%
Other than Pension Plans Post-retirement
Components of net periodic benefit cost:
Service cost	$ 3	$ 3	$ 3
Interest cost	6	7	7
Expected return on assets	(2)	(2)	(3)
Amortization of:
Actuarial loss	0	0	0
Prior service cost	0	0	1
Settlements	0	0	0
Special termination benefits	0	0	0
Net periodic benefit cost	$ 7	$ 8	$ 8
Weighted-average assumptions used to determine net periodic benefit cost for the year ended June 30:
Expected return on assets (as a percent)	6.75%	6.75%	7.00%
Other than Pension Plans Post-retirement | Minimum
Weighted-average assumptions used to determine benefit obligations at June 30:
Discount rate (as a percent)	2.70%	3.25%	3.75%
Weighted-average assumptions used to determine net periodic benefit cost for the year ended June 30:
Discount rate (as a percent)	3.25%	3.75%	3.70%
Other than Pension Plans Post-retirement | Maximum
Weighted-average assumptions used to determine benefit obligations at June 30:
Discount rate (as a percent)	9.00%	9.75%	9.75%
Weighted-average assumptions used to determine net periodic benefit cost for the year ended June 30:
Discount rate (as a percent)	9.75%	9.75%	9.75%