RISK MANAGEMENT ACTIVITIES AND FAIR VALUE MEASUREMENTS - NOTIONAL AMOUNTS AND FAIR VALUES OF QUALIFYING AND NON-QUALIFYING FINANCIAL INSTRUMENTS USED IN HEDGING TRANSACTIONS - ADDITIONAL INFORMATION (Details) - Underlying, Other - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Fair Value Hedging
Derivative [Line Items]
Underlying Debt Obligation, Carrying Amount	$ 7,860	$ 4,639
Net Investment Hedging
Derivative [Line Items]
Underlying Debt Obligation, Carrying Amount	$ 17,154	$ 15,012