Contractual Commitments, Contingencies, and Off-Balance Sheet Arrangements - Data Center Agreements - Capitalized Costs (Details) $ in Millions	12 Months Ended
	Jun. 30, 2020 USD ($)
Capitalized Contract Cost [Roll Forward]
Capitalized costs, beginning balance	$ 67.3
Capitalized costs incurred	1.8
Impact of foreign currency exchange	(0.2)
Total capitalized costs, ending balance	68.9
Total accumulated amortization	(44.4)
Net Deferred IBM Costs	24.5
Amended IT Services Agreement
Capitalized Contract Cost [Roll Forward]
Capitalized costs, beginning balance	62.3
Capitalized costs incurred	0.3
Impact of foreign currency exchange	0.0
Total capitalized costs, ending balance	62.6
Total accumulated amortization	(40.1)
Net Deferred IBM Costs	22.5
EU Information Technology Services Agreement
Capitalized Contract Cost [Roll Forward]
Capitalized costs, beginning balance	5.0
Capitalized costs incurred	1.6
Impact of foreign currency exchange	(0.2)
Total capitalized costs, ending balance	6.3
Total accumulated amortization	(4.3)
Net Deferred IBM Costs	$ 2.0