Income Taxes - Schedule of Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Current:
Federal	$ 0.0	$ 0.0	$ 0.0
State	0.6	1.3	0.4
Foreign	4.6	13.6	11.5
Current income tax expense	5.2	14.9	11.9
Deferred:
Federal	0.0	0.0	(14.1)
State	0.0	0.0	(3.2)
Foreign	(1.5)	4.7	(3.8)
Deferred income tax expense	(1.5)	4.7	(21.1)
Total	$ 3.7	$ 19.6	$ (9.2)