Segment Information - Revenue and Long-Lived Assets by Geographic Region (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues	$ 2,141	$ 2,062	$ 2,280	$ 2,150	$ 2,186	$ 2,078	$ 2,238	$ 2,072	$ 8,633	$ 8,574	$ 8,891
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									3,800	3,500	3,700
Australia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									2,300	2,600	2,800
U.K. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenues									$ 1,600	$ 1,800	$ 1,800