Income Taxes - Summary of Recognized Deferred Income Taxes in Balance Sheets (Detail) - USD ($) $ in Millions	Jun. 30, 2018	Jun. 30, 2017
Income Tax Disclosure [Abstract]
Deferred income tax assets	$ 279	$ 525
Deferred income tax liabilities	(389)	(61)
Net deferred tax (liabilities) assets	$ (110)
Net deferred tax (liabilities) assets		$ 464