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, 2019	Jun. 30, 2019
Foreign Currency Derivatives [Member] | Cash Flow Hedging [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, reported under other current assets		$ 1
Cross Currency Interest Rate Derivatives [Member] | Cash Flow Hedging [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, reported under other current assets		33
Derivatives, reported under other non-current assets	$ 93	83
Derivatives, reported under other non-current liabilities	(19)	(18)
Cross Currency Interest Rate Derivatives [Member] | Fair Value Hedging [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, reported under other current assets		8
Derivatives, reported under other non-current assets	23	21
Cross Currency Interest Rate Derivatives [Member] | Not Designated as Hedging Instrument, Economic Hedge [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, reported under other current assets		12
Interest Rate Contract [Member] | Cash Flow Hedging [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, reported under other current liabilities	(1)	(2)
Derivatives, reported under other non-current liabilities	$ (18)	$ (18)