POSTRETIREMENT BENEFITS AND EMPLOYEE STOCK OWNERSHIP PLAN - RECONCILIATION OF BENEFIT PLANS RECOGNIZED IN THE BALANCE SHEET (Details) - USD ($) $ in Millions	Jun. 30, 2022	Jun. 30, 2021
Pension Plan
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Assets for Plan Benefits, Defined Benefit Plan	$ 765	$ 88
Liability, Defined Benefit Plan, Current	(61)	(64)
Liability, Defined Benefit Plan, Noncurrent	(3,139)	(5,452)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	(2,435)	(5,428)
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax	1,906	4,869
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax	170	198
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax	2,076	5,067
Other Retiree Benefits
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Assets for Plan Benefits, Defined Benefit Plan	4,525	3,193
Liability, Defined Benefit Plan, Current	(34)	(33)
Liability, Defined Benefit Plan, Noncurrent	(672)	(922)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	3,819	2,238
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax [Abstract]
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax	(1,093)	(504)
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax	(907)	(471)
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax	$ (2,000)	$ (975)