Investments, Debt Securities, Amortized Cost and Fair Value by Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Available-for-Sale Debt Securities, Amortized Cost [Abstract]
Due in one year or less	$ 19,293
Due after one year through five years	65,451
Due after five years through ten years	58,962
Due after ten years	136,845
Amortized cost	280,551	$ 237,807
Available-for-Sale Debt Securities, Fair Value [Abstract]
Due in one year or less	19,530
Due after one year through five years	68,561
Due after five years through ten years	60,506
Due after ten years	139,241
Fair value	$ 287,838	$ 240,706

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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