Investments - Gross Realized Gains and Losses (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Debt securities:
Gross realized gains	$ 27	$ 720
Gross realized losses	(6)	(4)
Total debt securities	21	716
Equity securities:
Gross realized gains	2,903	344
Gross realized losses		(132)
Total equity securities	2,903	212
Total net realized investment gains (losses)	$ 2,924	$ 928

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Amount of realized gain 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 of realized gain (loss) 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 of realized gain (loss) from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of realized gain (loss) on investment.

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