Investments - Schedule of Other Long-Term Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Long-Term Investment [Line Items]
Commercial mortgage loan participations	$ 899,085	$ 835,878
Other
Long-Term Investment [Line Items]
Commercial mortgage loan participations	54,169	40,295
Investment funds
Long-Term Investment [Line Items]
Commercial mortgage loan participations	$ 844,916	$ 795,583

Amount of long-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)(f))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-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(12))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 3: 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)(6))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1

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