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Borrowings - 2028 Notes - Narrative (Details) - USD ($) $ in Thousands	Jul. 23, 2025	Jun. 30, 2026	Sep. 30, 2025	Jul. 16, 2025
Debt Instrument [Line Items]
Outstanding principal amount		$ 5,123,322	$ 4,661,461
2028 Notes
Debt Instrument [Line Items]
Aggregate principal amount	$ 500,000
Outstanding principal amount		$ 500,000
Interest rate	5.45%
2028 Notes \| Interest rate swaps
Debt Instrument [Line Items]
Aggregate principal amount				$ 500,000
Fixed interest rate (as a percent)				5.45%
Floating interest rate				1.834%
2028 Notes \| Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Redemption price percentage	100.00%
2028 Notes \| Debt Instrument, Redemption, Period Two
Debt Instrument [Line Items]
Redemption price percentage	100.00%
Debt instrument, basis spread on variable rate	0.30%