Net Finance Costs - Summary of Net Finance Costs (Parenthetical) (Detail) $ in Millions	12 Months Ended
Jun. 30, 2021 USD ($) Programs	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)
Net Finance Costs [Line Items]
Interest capitalised	2.83%	4.14%	4.96%
Tax relief for capitalised interest	$ 74	$ 92	$ 74
Repayments of hybrid debt instruments	$ 8,395	$ 2,047	$ 2,604
Number of repurchase programs \| Programs	2
Hybrid Debt Repurchase Program [Member]
Net Finance Costs [Line Items]
Repayments of hybrid debt instruments	$ 3,402

The weighted average of interest and other costs that an entity incurs in connection with the borrowing of funds applicable to the borrowings of the entity that are outstanding during the period, other than borrowings made specifically for the purpose of obtaining a qualifying asset. [Refer: Weighted average [member]; Borrowings]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 23
-IssueDate 2020-01-01
-Paragraph 26
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=23&code=ifrs-tx-2020-en-r&anchor=para_26_b&doctype=Standard
-URIDate 2020-01-01

Name:	ifrs-full_CapitalisationRateOfBorrowingCostsEligibleForCapitalisation
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration