Employee Benefit Plans (Components Of Stock-Based Compensation Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Total pretax stock-based compensation expense	$ 175.3	$ 130.8	$ 167.3
Income tax benefit	43.0	32.2	41.6
Operating expenses
Defined Benefit Plan Disclosure [Line Items]
Total pretax stock-based compensation expense	17.9	13.7	16.9
Selling, general and administrative expenses
Defined Benefit Plan Disclosure [Line Items]
Total pretax stock-based compensation expense	133.9	99.1	131.2
System development and programming costs
Defined Benefit Plan Disclosure [Line Items]
Total pretax stock-based compensation expense	$ 23.5	$ 18.0	$ 19.2