Significant Transactions - BAM (Details) - Operating Segments - Financial Guarantee (HG Global) - USD ($) $ in Millions	3 Months Ended
Sep. 30, 2024	Mar. 31, 2025	Dec. 31, 2024	Jul. 01, 2024
Other Significant Transactions [Line Items]
Notes receivable, fair value disclosure		$ 389.2	$ 381.7	$ 387.4
Unrealized loss on deconsolidation of BAM	$ 114.5

Amount of gain (loss) from deconsolidation of subsidiary and derecognition of group of assets constituting transfer of business or nonprofit activity, excluding conveyance of oil and gas mineral rights and transfer of good or service in contract with customer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481203/810-10-50-1B

Name:	us-gaap_DeconsolidationGainOrLossAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration