POSTRETIREMENT BENEFITS AND EMPLOYEE STOCK OWNERSHIP PLAN - RECONCILIATION OF BENEFIT OBLIGATIONS AND PLAN ASSETS (Details) - USD ($) $ in Millions		12 Months Ended
		Jun. 30, 2019		Jun. 30, 2018		Jun. 30, 2017
Pension Plan
CHANGE IN BENEFIT OBLIGATION
Defined Benefit Plan, Benefit Obligation, Beginning of Year	[1],[2]	$ 15,658		$ 16,160
Defined Benefit Plan, Service Cost	[3]	259	[2]	280	[2]	$ 310
Defined Benefit Plan, Interest Cost		339	[2]	348	[2]	300
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant	[2]	12		13
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	[2]	9		12
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	[2]	1,587		(722)
Defined Benefit Plan, Acquisitions (Divestitures), Benefit Obligation	[2]	49		0
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits	[2]	13		8
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)	[2]	(283)		148
Defined Benefit Plan, Benefit Obligation, Benefits Paid	[2]	(606)		(589)
Defined Benefit Plan, Benefit Obligation, End of Year	[1],[2]	17,037		15,658		16,160
CHANGE IN PLAN ASSETS
Defined Benefit Plan, Fair Value of Plan Assets, Beginning of Year	[2]	11,267		10,829
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	[2]	739		553
Defined Benefit Plan Acquisitions Divestitures Plan Assets	[2]	4		0
Defined Benefit Plan, Plan Assets, Contributions by Employer	[2]	178		406
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant	[2]	12		13
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss)	[2]	(212)		55
Defined Benefit Plan, ESOP Debt Servicing	[2],[4]	0		0
Defined Benefit Plan, Plan Assets, Benefits Paid	[2]	(606)		(589)
Defined Benefit Plan, Fair Value of Plan Assets, End of Year	[2]	11,382		11,267		10,829
Defined Benefit Plan, Funded (Unfunded) Status of Plan	[2]	(5,655)		(4,391)
Other Retiree Benefits
CHANGE IN BENEFIT OBLIGATION
Defined Benefit Plan, Benefit Obligation, Beginning of Year	[1],[5]	4,778		5,187
Defined Benefit Plan, Service Cost	[3]	101	[5]	112	[5]	133
Defined Benefit Plan, Interest Cost		187	[5]	177	[5]	175
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant	[5]	76		73
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	[5]	0		(231)
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	[5]	37		(308)
Defined Benefit Plan, Acquisitions (Divestitures), Benefit Obligation	[5]	0		0
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits	[5]	8		7
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)	[5]	20		5
Defined Benefit Plan, Benefit Obligation, Benefits Paid	[5]	(243)		(244)
Defined Benefit Plan, Benefit Obligation, End of Year	[1],[5]	4,964		4,778		5,187
CHANGE IN PLAN ASSETS
Defined Benefit Plan, Fair Value of Plan Assets, Beginning of Year	[5]	3,259		3,831
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	[5]	1,918		(481)
Defined Benefit Plan Acquisitions Divestitures Plan Assets	[5]	0		0
Defined Benefit Plan, Plan Assets, Contributions by Employer	[5]	31		33
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant	[5]	76		73
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss)	[5]	(1)		(3)
Defined Benefit Plan, ESOP Debt Servicing	[4],[5]	56		50
Defined Benefit Plan, Plan Assets, Benefits Paid	[5]	(243)		(244)
Defined Benefit Plan, Fair Value of Plan Assets, End of Year	[5]	5,096		3,259		$ 3,831
Defined Benefit Plan, Funded (Unfunded) Status of Plan	[5]	$ 132		$ (1,519)

[1] For the pension benefit plans, the benefit obligation is the projected benefit obligation. For other retiree benefit plans, the benefit obligation is the accumulated postretirement benefit obligation.

[2] Primarily non-U.S.-based defined benefit retirement plans.

[3] Service cost includes amounts related to discontinued operations in fiscal year ended June 30, 2017, which are not material.

[4] Represents the net impact of ESOP debt service requirements, which is netted against plan assets for other retiree benefits.

[5] Primarily U.S.-based other postretirement benefit plans.