Borrowings - 2028 Notes (Narrative) (Details) - USD ($) $ in Thousands	Dec. 05, 2023	Sep. 30, 2025	Sep. 19, 2025	Sep. 30, 2024	Apr. 11, 2024
Debt Instrument [Line Items]
Long-term debt		$ 4,900,773		$ 4,599,430
2028 Notes
Debt Instrument [Line Items]
Debt instrument, face amount	$ 450,000		$ 250,000
Long-term debt		$ 700,000		$ 450,000
Interest rate	7.05%
Debt instrument, redemption price (as percent)	100.00%
Debt instrument, basis spread on variable rate	0.45%
2028 Notes | Interest Rate Swap
Debt Instrument [Line Items]
Fixed interest rate (as a percent)	7.31%		5.05%		7.31%
Basis spread on variable rate (as a percent)	3.327%		1.723%		2.835%
Notional amount	$ 225,000		$ 250,000		$ 225,000