Investments - Summarized Fair Value and Gross Unrealized Losses on Securities Available for Sale (Details) $ in Thousands	Sep. 30, 2022 USD ($) security	Dec. 31, 2021 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	251	404
Less than 12 months, Fair value	$ 265,467	$ 682,402
Less than 12 months, Unrealized losses	$ (28,438)	$ (13,818)
12 months or longer, Number of issues \| security	281	33
12 months or longer, Fair value	$ 379,129	$ 45,645
12 months or longer, Unrealized losses	$ (73,255)	$ (1,853)
Fixed Maturities \| U.S. government obligations and agencies
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	2	4
Less than 12 months, Fair value	$ 2,720	$ 18,913
Less than 12 months, Unrealized losses	$ (113)	$ (111)
12 months or longer, Number of issues \| security	5	4
12 months or longer, Fair value	$ 8,878	$ 5,016
12 months or longer, Unrealized losses	$ (891)	$ (223)
Fixed Maturities \| Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	123	249
Less than 12 months, Fair value	$ 136,528	$ 378,595
Less than 12 months, Unrealized losses	$ (17,249)	$ (7,468)
12 months or longer, Number of issues \| security	173	18
12 months or longer, Fair value	$ 202,294	$ 17,356
12 months or longer, Unrealized losses	$ (37,753)	$ (679)
Fixed Maturities \| Mortgage-backed and asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	116	145
Less than 12 months, Fair value	$ 121,753	$ 274,883
Less than 12 months, Unrealized losses	$ (10,259)	$ (5,969)
12 months or longer, Number of issues \| security	96	11
12 months or longer, Fair value	$ 157,818	$ 23,273
12 months or longer, Unrealized losses	$ (32,515)	$ (951)
Fixed Maturities \| Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	3	5
Less than 12 months, Fair value	$ 2,299	$ 9,811
Less than 12 months, Unrealized losses	$ (390)	$ (269)
12 months or longer, Number of issues \| security	7	0
12 months or longer, Fair value	$ 10,139	$ 0
12 months or longer, Unrealized losses	$ (2,096)	$ 0
Fixed Maturities \| Redeemable preferred stock
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	7	1
Less than 12 months, Fair value	$ 2,167	$ 200
Less than 12 months, Unrealized losses	$ (427)	$ (1)
12 months or longer, Number of issues \| security	0	0
12 months or longer, Fair value	$ 0	$ 0
12 months or longer, Unrealized losses	$ 0	$ 0

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
-Paragraph 5
-URI https://asc.fasb.org/extlink&oid=124269663&loc=SL82922890-210455

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Name Accounting Standards Codification
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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer, without an allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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