Borrowings - 2029 Notes (Narrative) (Details) - USD ($) $ in Thousands	Feb. 01, 2024	Sep. 30, 2025	Dec. 03, 2024	Sep. 30, 2024
Debt Instrument [Line Items]
Long-term debt		$ 4,900,773		$ 4,599,430
2029 Notes
Debt Instrument [Line Items]
Debt instrument, face amount	$ 600,000		$ 150,000
Long-term debt		$ 750,000		$ 600,000
Interest rate	6.00%
Debt instrument, redemption price (as percent)	100.00%
Debt instrument, basis spread on variable rate	0.35%
2029 Notes | Interest Rate Swap
Debt Instrument [Line Items]
Debt instrument, face amount	$ 750,000
2029 Notes | Interest Rate Swap | Tranche one
Debt Instrument [Line Items]
Debt instrument, face amount	$ 600,000
Fixed interest rate (as a percent)	6.248%
Basis spread on variable rate (as a percent)	2.444%
2029 Notes | Interest Rate Swap | Tranche two
Debt Instrument [Line Items]
Debt instrument, face amount			$ 150,000
Fixed interest rate (as a percent)			5.881%
Basis spread on variable rate (as a percent)			2.012%