Income Taxes - Reconciliation of U.S. Federal Statutory Rate to Effective Tax Rate Prior to Adoption of ASU 2023-09 (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2024
Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract]
Provision for taxes at U.S. statutory rate	$ 1,203.4	$ 1,115.1	$ 1,023.2
State taxes, net of federal tax benefit	151.0	128.0	120.6
Foreign rate differential	82.8	39.0	41.0
Excess tax benefit - Stock-based compensation		(24.3)	(17.1)
Other		(27.4)	(47.4)
Total provision for income taxes	$ 1,316.8	$ 1,230.4	$ 1,120.3
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Provision for taxes at U.S. statutory rate	21.00%	21.00%	21.00%
State taxes, net of federal tax benefit	2.60%	2.40%	2.50%
Foreign rate differential	1.50%	0.70%	0.90%
Excess tax benefit - Stock-based compensation		(0.40%)	(0.40%)
Other	(0.30%)	(0.50%)	(1.00%)
Effective tax rate	23.00%	23.20%	23.00%