Income Taxes - Schedule of Income Tax Net Operating Loss Carryforwards (NOLs) (Gross, Net Uncertain Tax Benefits) (Detail) $ in Millions	12 Months Ended
	Jun. 30, 2018 USD ($)
U.S. Federal [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards, Amount	$ 635
U.S. Federal [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards, expiration	Dec. 31, 2021
U.S. Federal [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards, expiration	Dec. 31, 2037
U.S. States [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards period expiration, description	Various
Net Operating Loss Carryforwards, Amount	$ 455
Foreign Tax Authority [Member] | Australia [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards period expiration, description	Indefinite
Net Operating Loss Carryforwards, Amount	$ 304
Foreign Tax Authority [Member] | U.K. [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards period expiration, description	Indefinite
Net Operating Loss Carryforwards, Amount	$ 4
Other Foreign [Member]
Operating Loss Carryforwards [Line Items]
Net Operating Loss Carryforwards period expiration, description	Various
Net Operating Loss Carryforwards, Amount	$ 423