Introduction (Details) $ / shares in Units, $ in Millions				9 Months Ended
	Aug. 25, 2026 USD ($) $ / shares shares	Apr. 17, 2026 USD ($) $ / shares shares	Apr. 16, 2026 $ / shares shares	Sep. 30, 2026 USD ($) segment vote	Sep. 30, 2025 USD ($)
Segment Reporting [Line Items]
Number of reportable segments | segment				2
Proceeds from the issuance of common stock | $				$ 4,917.6	$ 0.0
Common stock, ownership percentage (in percent)				0.590
Common stock, voting percentage (in percent)				0.931
IPO
Segment Reporting [Line Items]
Deferred offering costs | $		$ 8.8
Class A Common Stock
Segment Reporting [Line Items]
Cancelled shares (in shares)			1,000
Remeasurement and exchange of noncontrolling interests for Class A common stock (in shares)			81,791,959
Number of votes each share is entitled | vote				1
Proceeds from issuance of private placement | $	$ 2,250.0
Class A Common Stock | IPO
Segment Reporting [Line Items]
Sale of stock (in shares)		95,096,154
Sale of stock (in dollars per share) | $ / shares		$ 27.00	$ 27.00
Class A Common Stock | Private Placement
Segment Reporting [Line Items]
Sale of stock (in shares)	90,108,130
Sale of stock (in dollars per share) | $ / shares	$ 24.97
Deferred offering costs | $	$ 32.6
Class A Common Stock | Private Placement | Madison Solutions LLC
Segment Reporting [Line Items]
Sale of stock (in shares)	12,815,378
Class A Common Stock | Private Placement | Board of Directors Chairman
Segment Reporting [Line Items]
Sale of stock (in shares)	12,014,417
Class B Common Stock
Segment Reporting [Line Items]
Issued shares (in shares)			320,676,155
Number of votes each share is entitled | vote				10
Class B Common Stock | Private Placement
Segment Reporting [Line Items]
Sale of stock (in shares)		3,703,704
Sale of stock (in dollars per share) | $ / shares		$ 27.00
Proceeds from the issuance of common stock | $		$ 2,584.2