Investments - Summarized Fair Value and Gross Unrealized Losses on Securities Available for Sale (Details) $ in Thousands	Mar. 31, 2022 USD ($) security	Dec. 31, 2021 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	321	404
Less than 12 months, Fair value	$ 432,602	$ 682,402
Less than 12 months, Unrealized losses	$ (25,591)	$ (13,818)
12 months or longer, Number of issues \| security	171	33
12 months or longer, Fair value	$ 271,247	$ 45,645
12 months or longer, Unrealized losses	$ (27,720)	$ (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	$ 11,549	$ 18,913
Less than 12 months, Unrealized losses	$ (63)	$ (111)
12 months or longer, Number of issues \| security	5	4
12 months or longer, Fair value	$ 10,112	$ 5,016
12 months or longer, Unrealized losses	$ (656)	$ (223)
Fixed Maturities \| Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	188	249
Less than 12 months, Fair value	$ 253,022	$ 378,595
Less than 12 months, Unrealized losses	$ (16,821)	$ (7,468)
12 months or longer, Number of issues \| security	95	18
12 months or longer, Fair value	$ 118,710	$ 17,356
12 months or longer, Unrealized losses	$ (12,044)	$ (679)
Fixed Maturities \| Mortgage-backed and asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	118	145
Less than 12 months, Fair value	$ 156,773	$ 274,883
Less than 12 months, Unrealized losses	$ (7,653)	$ (5,969)
12 months or longer, Number of issues \| security	70	11
12 months or longer, Fair value	$ 138,894	$ 23,273
12 months or longer, Unrealized losses	$ (14,547)	$ (951)
Fixed Maturities \| Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	9	5
Less than 12 months, Fair value	$ 9,988	$ 9,811
Less than 12 months, Unrealized losses	$ (932)	$ (269)
12 months or longer, Number of issues \| security	1	0
12 months or longer, Fair value	$ 3,531	$ 0
12 months or longer, Unrealized losses	$ (473)	$ 0
Fixed Maturities \| Redeemable preferred stock
Debt Securities, Available-for-sale [Line Items]
Less than 12 months, Number of issues \| security	4	1
Less than 12 months, Fair value	$ 1,270	$ 200
Less than 12 months, Unrealized losses	$ (122)	$ (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
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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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.

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