Revenue Recognition (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Dec. 31, 2019	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Contract liabilities, current		$ 396.4	$ 403.2
Contract liabilities, noncurrent		218.8	267.5
Revenue recognized that was previously recorded in contract liabilities		400.5	478.4
Write-off of contract liabilities	$ 42.7
Write-off of offsetting contract costs		0.0	42.7	$ 0.0
Capitalized contract cost, net		406.0	434.8
Current portion of subscription acquisition costs		225.6	213.2
Noncurrent portion of subscription acquisition costs		180.4	221.6
Contract amortization		213.2	238.1	$ 319.5
Subscription Acquisition Costs, Current
Disaggregation of Revenue [Line Items]
Current portion of subscription acquisition costs		225.6	213.2
Subscription Acquisition Costs, Noncurrent
Disaggregation of Revenue [Line Items]
Noncurrent portion of subscription acquisition costs		$ 180.4	$ 221.6

Amount of amortization expense for asset recognized from cost incurred to obtain or fulfill contract with customer.

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