Investments - Summary of Amortized Cost and Fair Values of Fixed Maturity Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Cost	$ 40,044	$ 35,562
Gross unrealized gains	399	703
Gross unrealized losses	(195)	(11)
Fair value	40,248	36,254
U.S. Treasury securities, obligations of U.S. Government agencies and municipalities
Debt Securities, Available-for-sale [Line Items]
Cost	31,756	28,372
Gross unrealized gains	239	464
Gross unrealized losses	(172)	(5)
Fair value	31,823	28,831
Corporate debt
Debt Securities, Available-for-sale [Line Items]
Cost	8,288	7,190
Gross unrealized gains	160	239
Gross unrealized losses	(23)	(6)
Fair value	$ 8,425	$ 7,423

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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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).

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