Additional Financial Information - Components of Other, Net Included in Statement of Operations (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Jun. 30, 2018		Jun. 30, 2017		Jun. 30, 2016
REA Group [Member]
Components of Other Income (Expense) [Line Items]
Gain on sale of business	$ 120	$ 0	[1]	$ 107	[1]	$ 0	[1]

[1] The Company recognized a pre-tax gain of $107 million for the fiscal year ended June 30, 2017 related to REA Group's sale of its European business. See Note 3-Acquisitions, Disposals and Other Transactions.