Additional Financial Information - Components of Other, Net Included in Statement of Operations (Detail) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Other Income and Expenses [Line Items]
Remeasurement of equity securities		$ 81	$ (21)	$ (23)
Total Other, net		143	9	33
REA Group | Equity Method Investments
Other Income and Expenses [Line Items]
Gain on sale of businesses			20
Move Inc | Top Producer
Other Income and Expenses [Line Items]
Gain on sale of businesses		18
Nonoperating Income (Expense)
Other Income and Expenses [Line Items]
Remeasurement of equity securities		81	(21)	(23)
Dividends received from equity security investments		9	3	24
Gain on sale of Australian property		0	0	16
Gain on remeasurement of previously-held interest in Elara	$ 7	7	0	0
Other		28	7	16
Total Other, net		143	9	33
Nonoperating Income (Expense) | REA Group
Other Income and Expenses [Line Items]
Gain on sale of businesses		$ 18	$ 20	$ 0