Employee Benefit Plans - Defined Benefit Pension Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Rabbi trust assets	$ 62.6	$ 54.5
Benefit expense	6.1	5.2	$ 4.4
Benefit obligation	65.9	59.8	50.8
SORP | Supplemental Employee Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Benefit expense	5.6	4.8	3.9
Benefit obligation	59.5	53.8	45.5
SERP | Supplemental Employee Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Benefit expense	0.5	0.4	0.5
Benefit obligation	$ 6.4	$ 6.0	$ 5.4