Subsequent Events (Details) $ / shares in Units, shares in Millions, $ in Millions			1 Months Ended			3 Months Ended
	Jan. 01, 2026 USD ($)	Dec. 29, 2025 USD ($)	Feb. 28, 2026 $ / shares	Jan. 31, 2026 USD ($) $ / shares shares	Sep. 30, 2025 USD ($)	Dec. 31, 2025 USD ($)
Primary Beneficiary | The Fund
Subsequent Event [Line Items]
Investment company, committed capital		$ 816.3			$ 716.0
Capital calls						$ 486.4
Ownership interest (as a percent)						69.00%
Subsequent event
Subsequent Event [Line Items]
Common stock dividend declared (in dollars per share) | $ / shares			$ 0.2700	$ 0.2700
Repurchase of common stock				$ 101.9
Number of shares repurchased | shares				1.8
Subsequent event | Senior Notes | 3.500% Convertible Senior Notes Due January 2029
Subsequent Event [Line Items]
Face amount of loan				$ 862.5
Stated interest rate (as a percent)				3.50%
Estimated net proceeds				$ 845.5
Conversion ratio				0.0144051
Conversion price (in dollars per share) | $ / shares				$ 69.42
Subsequent event | Primary Beneficiary | The Fund
Subsequent Event [Line Items]
Capital calls	$ 638.0
Redemption of units	$ 408.2
Ownership interest (as a percent)	38.50%