Amount of short-term investments classified as other.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(1)(g))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(8))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.5)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1

Name:	us-gaap_OtherShortTermInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Significant Transactions - Outrigger Re (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Jan. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Mar. 31, 2024
Outrigger Re
Other Significant Transactions [Line Items]
Contributions to subsidiaries			$ 205.0
Outrigger Re
Other Significant Transactions [Line Items]
Ceded unearned premiums			$ 250.0
Rollover amount		$ 130.0
Short-term investments, at fair value		$ 265.3		$ 222.4
Return of capital	$ 68.1