Share-Based Compensation (Schedule of Total Share-Based Compensation Expense by Type of Award) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation	$ 21	$ 22	$ 41	$ 41
Restricted Share Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation	16	16	33	30
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation	1	2	2	6
Performance Share Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation	$ 4	$ 4	$ 6	$ 5