Significant Transactions - Bamboo (Details) - USD ($) $ in Millions			12 Months Ended
	Dec. 05, 2025	Jan. 02, 2024	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Mar. 31, 2024
Other Significant Transactions [Line Items]
Net cash proceeds			$ 746.5	$ 0.0	$ 17.3
Common equity securities, at fair value			483.0	650.0
Net gain on sale of the Bamboo Group			849.3	$ 0.0	$ 0.0
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Other Significant Transactions [Line Items]
Net gain on sale of the Bamboo Group			33.0
Bamboo Group | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Other Significant Transactions [Line Items]
Net cash proceeds	$ 847.9
Proceeds held in escrow			3.6
Net gain			816.3
Net gain on sale of the Bamboo Group			$ 849.3
Variable Interest Entity, Not Primary Beneficiary | Bamboo SPV
Other Significant Transactions [Line Items]
Ownership interest			27.90%
Bamboo Ide8 Insurance Services LLC
Other Significant Transactions [Line Items]
Contributions to subsidiaries		$ 296.7
Contributions to retire credit facility		36.0
Cash contributions for transaction		$ 20.0
Basic ownership		72.80%
Ownership percentage, after equity incentives		63.70%
Assets and goodwill acquired		$ 479.5
Liabilities acquired		91.7
Noncontrolling interest acquired		111.1
Assets including goodwill		371.4
Transaction costs		$ 4.0				$ 0.3
Bamboo Ide8 Insurance Services LLC | Bamboo Management
Other Significant Transactions [Line Items]
Basic ownership		16.10%
Ownership percentage, after equity incentives		26.60%
Bamboo Group
Other Significant Transactions [Line Items]
Basic ownership			17.20%
Equity interest percent of ownership sold	77.30%
Common equity securities, at fair value	$ 250.0
Ownership percentage, fully diluted			14.60%
Bamboo Group | Bamboo Group | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Other Significant Transactions [Line Items]
Net gain on sale of the Bamboo Group			$ 188.6