Investments - Net Investment Income (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Net investment income
Interest income	$ 3,082	$ 2,262	$ 5,640	$ 4,501
Dividend income	185	58	340	157
Investment expenses	(127)	(126)	(261)	(245)
Net investment income	$ 3,140	$ 2,194	$ 5,719	$ 4,413

Amount of dividend income on nonoperating securities.

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Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

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Amount of expenses related to the generation of investment income.

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Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities.

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