Acquisitions, Disposals and Other Transactions - Additional Information (Detail) £ / shares in Units, € in Millions, £ in Millions, $ in Millions, $ in Millions				1 Months Ended									3 Months Ended			12 Months Ended
		Jul. 31, 2017 USD ($)	Jul. 31, 2017 AUD ($)	Oct. 31, 2018 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2018 AUD ($)	Apr. 30, 2018 USD ($)	Jul. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2016 EUR (€)	Sep. 30, 2016 USD ($)	Sep. 30, 2016 GBP (£) £ / shares	Dec. 31, 2019	Jun. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 AUD ($)
Schedule Of Business Acquisitions And Divestitures [Line Items]
Total transaction value	[1]																$ 914
Acquisition cost recognized as compensation expense, period for recognition													3 years
Goodwill					$ 5,218									$ 5,218		$ 5,147	5,218	$ 3,838
Long term debt					1,952									1,952		$ 1,453	1,952
REA Group [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Company ownership percentage									61.60%	61.60%
Cash consideration of sale of business									$ 140	€ 133
Gain on sale of business																		107
Wireless Group Plc [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition, cost of acquired entity, cash paid											$ 285	£ 220
Goodwill											115
Business acquisition purchase price allocation, Outstanding borrowings											23
Business acquisition purchase price allocation, amortizable and indefinite-lived intangible assets											220
Business acquisition, cost of acquired entity per share | £ / shares												£ 3.15
Hometrack Australia Pty Ltd [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition, cost of acquired entity, cash paid					100	$ 130
Business acquisition purchase price allocation, amortizable intangible assets					25									25			25
Goodwill					74									74			74
Long term debt					$ 53									53			$ 53		$ 70
Smartline Home Loans Pty Limited [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition, cost of acquired entity, cash paid		$ 55	$ 70
Goodwill		$ 49						$ 49
Business acquisition, acquired interest percentage		80.30%						80.30%
Non-controlling ownership percentage		19.70%						19.70%
Starting period to sell remaining interest in minority shareholders															After three years
Mandatorily redeemable period after closing, if option is not exercised															4 years
Minority interest value															$ 12
Australian Regional Media [Member] | REA Group [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition, cost of acquired entity, cash paid																		$ 62
Foxtel [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Total transaction value							$ 331
Cash acquired							78
Goodwill							$ 1,559
Equity method investment, ownership percentage							50.00%
Ownership interest																65.00%
Percentage of the entity that the excess purchase price valuation is based on							100.00%
Business acquisition purchase price allocation, tangible assets							$ 871
Business acquisition purchase price allocation, Outstanding borrowings							1,751
Business acquisition purchase price allocation, amortizable and indefinite-lived intangible assets							861
Business Assets Acquired							4,225
Business acquisition, purchased technology amount							967
Minority interest value							$ 578
Opcity [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Total transaction value				$ 210
Business acquisition, cost of acquired entity, cash paid				182
Cash acquired				7
Cash held back after closing				20
Deferred compensation related to business acquisition				28
Goodwill				124
Business Assets Acquired				$ 73
Opcity [Member] | Purchased technology
Schedule Of Business Acquisitions And Divestitures [Line Items]
Purchased technology, weighted average useful life				12 years
Business acquisition, purchased technology amount				$ 49
Opcity [Member] | Leads and Customer Relationships [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, amortizable intangible assets				$ 24
Finite lived intangible assets, weighted average useful life				9 years
FOX SPORTS Australia [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Company ownership percentage							100.00%
Write-off of channel distribution agreement intangible asset														317
FOX SPORTS Australia [Member] | Foxtel [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Company ownership percentage																65.00%
Foxtel and Fox Sports Australia [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Loss on transactions														$ (337)
Subscriber Relationships [Member] | Foxtel [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, amortizable intangible assets							$ 468
Finite lived intangible assets, weighted average useful life							10 years
Trade Names [Member] | Foxtel [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, indefinite-lived intangible assets							$ 270
Customer Relationships [Member] | Wireless Group Plc [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, amortizable intangible assets											$ 8
Finite lived intangible assets, weighted average useful life											6 years	6 years
Customer Relationships [Member] | Hometrack Australia Pty Ltd [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Finite lived intangible assets, weighted average useful life																	15 years
Customer Relationships [Member] | Smartline Home Loans Pty Limited [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, amortizable intangible assets		$ 19						$ 19
Finite lived intangible assets, weighted average useful life								16 years
Customer Relationships [Member] | Foxtel [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Finite lived intangible assets, weighted average useful life							15 years
Business acquisition purchase price allocation, amortizable and indefinite-lived intangible assets							$ 123
Technology [Member] | Hometrack Australia Pty Ltd [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Finite lived intangible assets, weighted average useful life																	8 years
Broadcast Licenses [Member] | Wireless Group Plc [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, indefinite-lived intangible assets											$ 185
Trademarks [Member] | Wireless Group Plc [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, indefinite-lived intangible assets											$ 27
Telstra [Member] | Foxtel [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Ownership interest held by minority interest																35.00%

[1] See Note 4 —Acquisitions, Disposals and Other Transactions.