Stock-Based Compensation (Summary of Stock-based Compensation Expense Liability and Equity Classified Awards Included in Consolidated Statements of Operations) (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 27.8	$ 32.0
Operating Costs [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	3.2	3.3
Selling, General and Administrative Expenses [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	24.6	28.7
Part A Restricted Stock Units [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	22.2	21.3
Part B Restricted Stock Units [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	5.1	6.2
Part C Restricted Stock Units [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 0.5	0.3
CII [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense		$ 4.2