Employee Benefit Plans (Components Of Stock-Based Compensation Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Stock-based compensation expense	$ 130.8	$ 167.3	$ 175.4
Income Tax Benefit	32.2	41.6	44.1
Operating Expenses [Member]
Defined Benefit Plan Disclosure [Line Items]
Stock-based compensation expense	13.7	16.9	22.9
Selling, General and Administrative Expenses [Member]
Defined Benefit Plan Disclosure [Line Items]
Stock-based compensation expense	99.1	131.2	128.7
System Development And Programming Costs [Member]
Defined Benefit Plan Disclosure [Line Items]
Stock-based compensation expense	$ 18.0	$ 19.2	$ 23.8