Summary of Investments - Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Available-For-Sale, Amortized Cost
Due in one year or less	$ 68,441
Due after one year through five years	481,816
Due after five years through 10 years	436,135
Due after 10 years	409,032
Available-For-Sale, Fair Value
Due in one year or less	68,665
Due after one year through five years	483,944
Due after five years through 10 years	429,261
Due after 10 years	405,257
Fair Value	1,651,468	$ 1,719,790
Asset-backed securities
Available-For-Sale, Amortized Cost
Securities not categorized by contractual maturity	327
Amortized Cost	327	325
Available-For-Sale, Fair Value
Securities not categorized by contractual maturity	889
Fair Value	889	925
Mortgage-backed securities
Available-For-Sale, Amortized Cost
Securities not categorized by contractual maturity	23,293
Amortized Cost	23,293	25,075
Available-For-Sale, Fair Value
Securities not categorized by contractual maturity	22,018
Fair Value	22,018	$ 25,013
Collateralized mortgage obligations
Available-For-Sale, Amortized Cost
Securities not categorized by contractual maturity	252,714
Available-For-Sale, Fair Value
Securities not categorized by contractual maturity	241,434
Fixed maturities
Available-For-Sale, Amortized Cost
Amortized Cost	1,671,758
Available-For-Sale, Fair Value
Fair Value	$ 1,651,468

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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