Financial Instruments and Fair Value Measurements - Summary of Assets and Liabilities Measured At Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Jun. 30, 2020
Assets:
Equity securities	$ 197	$ 177
Fair Value, Recurring
Assets:
Equity securities	197	177
Total assets	305	299
Liabilities:
Total liabilities	36	37
Fair Value, Recurring | Foreign currency derivatives | Cash Flow Hedging
Liabilities:
Derivative liabilities	3	3
Fair Value, Recurring | Cross currency interest rate derivatives | Fair Value Hedging
Assets:
Derivative assets	21	24
Fair Value, Recurring | Cross currency interest rate derivatives | Cash Flow Hedging
Assets:
Derivative assets	87	98
Liabilities:
Derivative liabilities	18	18
Fair Value, Recurring | Interest rate derivatives | Cash Flow Hedging
Liabilities:
Derivative liabilities	15	16
Fair Value, Recurring | Level 1
Assets:
Equity securities	68	54
Total assets	68	54
Liabilities:
Total liabilities	0	0
Fair Value, Recurring | Level 1 | Foreign currency derivatives | Cash Flow Hedging
Liabilities:
Derivative liabilities	0	0
Fair Value, Recurring | Level 1 | Cross currency interest rate derivatives | Fair Value Hedging
Assets:
Derivative assets	0	0
Fair Value, Recurring | Level 1 | Cross currency interest rate derivatives | Cash Flow Hedging
Assets:
Derivative assets	0	0
Liabilities:
Derivative liabilities	0	0
Fair Value, Recurring | Level 1 | Interest rate derivatives | Cash Flow Hedging
Liabilities:
Derivative liabilities	0	0
Fair Value, Recurring | Level 2
Assets:
Equity securities	0	0
Total assets	108	122
Liabilities:
Total liabilities	36	37
Fair Value, Recurring | Level 2 | Foreign currency derivatives | Cash Flow Hedging
Liabilities:
Derivative liabilities	3	3
Fair Value, Recurring | Level 2 | Cross currency interest rate derivatives | Fair Value Hedging
Assets:
Derivative assets	21	24
Fair Value, Recurring | Level 2 | Cross currency interest rate derivatives | Cash Flow Hedging
Assets:
Derivative assets	87	98
Liabilities:
Derivative liabilities	18	18
Fair Value, Recurring | Level 2 | Interest rate derivatives | Cash Flow Hedging
Liabilities:
Derivative liabilities	15	16
Fair Value, Recurring | Level 3
Assets:
Equity securities	129	123
Total assets	129	123
Liabilities:
Total liabilities	0	0
Fair Value, Recurring | Level 3 | Foreign currency derivatives | Cash Flow Hedging
Liabilities:
Derivative liabilities	0	0
Fair Value, Recurring | Level 3 | Cross currency interest rate derivatives | Fair Value Hedging
Assets:
Derivative assets	0	0
Fair Value, Recurring | Level 3 | Cross currency interest rate derivatives | Cash Flow Hedging
Assets:
Derivative assets	0	0
Liabilities:
Derivative liabilities	0	0
Fair Value, Recurring | Level 3 | Interest rate derivatives | Cash Flow Hedging
Liabilities:
Derivative liabilities	$ 0	$ 0