Financial Instruments and Fair Value Measurements - Summary of Hedges Classified as Current or Non-Current in Balance Sheets Based on Maturity Dates (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Jun. 30, 2020
Foreign currency derivatives | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, reported under other current liabilities	$ (3)	$ (3)
Cross currency interest rate derivatives | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, reported under other non-current assets	87	98
Derivatives, reported under other non-current liabilities	(18)	(18)
Cross currency interest rate derivatives | Fair Value Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, reported under other non-current assets	21	24
Interest rate derivatives | Cash Flow Hedging
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, reported under other non-current liabilities	$ (15)	$ (16)