Investments - Schedule of Available-for-Sale Investments (Detail) - USD ($) $ in Millions		Dec. 31, 2016	Jun. 30, 2016
Investments Schedule [Abstract]
Cost basis of available-for-sale investments		$ 125	$ 155
Accumulated gross unrealized gain		1	34
Accumulated gross unrealized loss		0	0
Fair value of available-for-sale investments	[1]	126	189
Net deferred tax (asset) liability		$ 0	$ 13

[1] Available-for-sale securities primarily include the Company's investments in APN and The Rubicon Project, Inc. During fiscal 2016, the Company participated in an entitlement offer to maintain its 14.99% interest in APN for $20 million. During the three months ended December 31, 2016, the Company participated in an entitlement offer for $21 million and its interest was diluted from 14.99% to 13.23%. APN operates a portfolio of Australian radio and outdoor media assets.