Debt - Schedule of Long Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024
Debt Instrument [Line Items]
Notes payable	$ 4,003.5		$ 3,004.1
Less: current portion	(1,000.5)		(1.1)
Less: unamortized discount and debt issuance costs	(21.0)		(11.7)
Long-term debt	$ 2,982.0		2,991.3
Fixed-rate 3.375% notes due September 15, 2025
Debt Instrument [Line Items]
Stated interest rate	3.375%
Debt instrument effective rate (in percent)	3.47%
Notes payable	$ 1,000.0		1,000.0
Fixed-rate 1.700% notes due May 15, 2028
Debt Instrument [Line Items]
Stated interest rate	1.70%
Debt instrument effective rate (in percent)	1.85%
Notes payable	$ 1,000.0		1,000.0
Fixed-rate 1.250% notes due September 1, 2030
Debt Instrument [Line Items]
Stated interest rate	1.25%
Debt instrument effective rate (in percent)	1.83%
Notes payable	$ 1,000.0		1,000.0
Fixed-rate 4.450% notes due September 9, 2034 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate	4.45%	4.45%
Debt instrument effective rate (in percent)	4.75%
Notes payable	$ 1,000.0		0.0
Other
Debt Instrument [Line Items]
Notes payable	$ 3.5		$ 4.1