Segment Information - Revenue and Long-Lived Assets by Geographic Region Footnote (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Total Revenues	$ 1,923	$ 2,266	$ 2,479	$ 2,340	$ 2,466	$ 2,457	$ 2,627	$ 2,524	$ 9,008	$ 10,074	$ 9,024
Domestic
Segment Reporting Information [Line Items]
Total Revenues									3,700	3,900	3,900
U.K.
Segment Reporting Information [Line Items]
Total Revenues									1,200	1,300	1,400
Australia
Segment Reporting Information [Line Items]
Total Revenues									$ 3,500	$ 4,000	$ 2,900