RISK MANAGEMENT ACTIVITIES AND FAIR VALUE MEASUREMENTS - ADDITIONAL INFORMATION (Details) - USD ($) $ in Millions	Sep. 30, 2020	Jun. 30, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash Equivalents, at Carrying Value	$ 12,200	$ 14,600
Derivatives in Fair Value Hedging Relationships | Underlying, Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Underlying Debt Obligation, Carrying Amt	7,600	7,400
Derivatives in Net Investment Hedging Relationships | Underlying, Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Underlying Debt Obligation, Carrying Amt	12,500	16,000
Long-term Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term Debt, Fair Value	29,500	29,000
Long Term Debt, Current Maturities Measured at Fair Value	2,500	2,500
Other Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, Fair Value Disclosure	$ 66	$ 67