Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis (Details) - Measured at Fair Value on Recurring Basis - USD ($) $ in Millions	Sep. 30, 2021	Jun. 30, 2021
Recurring fair value measurements
Cash and cash equivalents - cash equivalents	$ 87.5	$ 112.6
Accrued expenses
Contingent consideration		2.2
Deferred compensation plans	2.1	2.1
Other noncurrent liabilities
Contingent consideration	1.0	1.6
Deferred compensation plans	14.3	13.6
Total recurring liability fair value measurements	17.4	19.5
Level 1
Recurring fair value measurements
Cash and cash equivalents - cash equivalents	87.5	112.6
Accrued expenses
Contingent consideration		0.0
Deferred compensation plans	0.0	0.0
Other noncurrent liabilities
Contingent consideration	0.0	0.0
Deferred compensation plans	0.0	0.0
Total recurring liability fair value measurements	0.0	0.0
Level 2
Recurring fair value measurements
Cash and cash equivalents - cash equivalents	0.0	0.0
Accrued expenses
Contingent consideration		0.0
Deferred compensation plans	2.1	2.1
Other noncurrent liabilities
Contingent consideration	0.0	0.0
Deferred compensation plans	14.3	13.6
Total recurring liability fair value measurements	16.4	15.7
Level 3
Recurring fair value measurements
Cash and cash equivalents - cash equivalents	0.0	0.0
Accrued expenses
Contingent consideration		2.2
Deferred compensation plans	0.0	0.0
Other noncurrent liabilities
Contingent consideration	1.0	1.6
Deferred compensation plans	0.0	0.0
Total recurring liability fair value measurements	$ 1.0	$ 3.8