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		6 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 34.5	$ 42.9	$ 66.5	$ 89.0
Operating Costs [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	3.3	5.1	6.6	11.8
Selling, General and Administrative Expenses [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	31.2	37.8	59.9	77.2
Part A Restricted Stock Units [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	18.8	10.2	40.1	20.2
Part B Restricted Stock Units [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	9.5	6.0	15.7	22.4
Part C Restricted Stock Units [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	0.3	0.3	0.6	0.5
CII [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 5.9	$ 26.4	$ 10.1	$ 45.9