Borrowings - Schedule of Borrowings (Parenthetical) (Detail) $ in Millions	12 Months Ended
	Jun. 30, 2018 USD ($)
Foxtel [Member]
Debt and Financial Instruments [Line Items]
Undrawn commitments	$ 198
Percentage of applicable margin payable as commitment fee	40% and 45% of the applicable margin
Minimum [Member] | Australian BBSY [Member]
Debt and Financial Instruments [Line Items]
Interest rate margin	1.10%
Maximum [Member] | Australian BBSY [Member]
Debt and Financial Instruments [Line Items]
Interest rate margin	2.70%
REA Group [Member] | Minimum [Member]
Debt and Financial Instruments [Line Items]
Interest rate margin	0.95%
REA Group [Member] | Minimum [Member] | Australian BBSY [Member]
Debt and Financial Instruments [Line Items]
Interest rate margin	0.85%
REA Group [Member] | Maximum [Member]
Debt and Financial Instruments [Line Items]
Interest rate margin	1.05%
REA Group [Member] | Maximum [Member] | Australian BBSY [Member]
Debt and Financial Instruments [Line Items]
Interest rate margin	1.45%