INCOME TAXES - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2023
Income tax reconciliation
Provision for income taxes at U.S. statutory rate	$ 222.3	$ 184.2	$ 166.9
Increase (decrease) in Provision for income taxes from:
State taxes, net of federal tax	24.9	20.5	23.7
Foreign rate differential	2.3	5.8	2.7
Valuation allowances	0.3	0.5	(0.3)
Stock-based compensation - excess tax benefits (“ETB”)	(20.5)	(12.9)	(10.4)
Tax Credits and Foreign-Derived Intangible Income Deduction (“FDII”)	(10.4)	(21.2)	(20.2)
Other	0.4	2.2	1.9
Total Provision for income taxes	$ 219.2	$ 179.3	$ 164.3
Tax rate reconciliation (percent)
Provision for income taxes at U.S. statutory rate	21.00%	21.00%	21.00%
Increase (decrease) in Provision for income taxes from:
State taxes, net of federal tax	2.40%	2.30%	3.00%
Foreign rate differential	0.20%	0.70%	0.30%
Valuation allowances	0.00%	0.10%	0.00%
Stock-based compensation - excess tax benefits (“ETB”)	(1.90%)	(1.50%)	(1.30%)
Tax Credits and Foreign-Derived Intangible Income Deduction (“FDII”)	(1.00%)	(2.40%)	(2.50%)
Other	0.00%	0.30%	0.20%
Total Provision for income taxes	20.70%	20.40%	20.70%