Equity Method Eligible Investments - Carrying Value and Ownership Percentages (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Kudu’s Participation Contracts
Investments in and Advances to Affiliates [Line Items]
Carrying Value	$ 1,285.0	$ 1,008.4
Bamboo SPV
Investments in and Advances to Affiliates [Line Items]
Ownership Interest	27.90%	0.00%
Carrying Value	$ 250.0	$ 0.0
Investment in MediaAlpha
Investments in and Advances to Affiliates [Line Items]
Ownership Interest	27.40%	26.60%
Carrying Value	$ 231.2	$ 201.6
PassportCard/DavidShield
Investments in and Advances to Affiliates [Line Items]
Ownership Interest	53.80%	53.80%
Carrying Value	$ 170.0	$ 150.0
BroadStreet SPV
Investments in and Advances to Affiliates [Line Items]
Ownership Interest	10.90%	0.00%
Carrying Value	$ 160.0	$ 0.0
Elementum
Investments in and Advances to Affiliates [Line Items]
Ownership Interest	26.60%	26.60%
Carrying Value	$ 35.0	$ 35.0
Other equity method eligible investments (3)
Investments in and Advances to Affiliates [Line Items]
Carrying Value	$ 266.0	$ 243.7
Minimum | Kudu’s Participation Contracts
Investments in and Advances to Affiliates [Line Items]
Ownership Interest	4.10%	4.10%
Maximum | Kudu’s Participation Contracts
Investments in and Advances to Affiliates [Line Items]
Ownership Interest	30.00%	30.00%