General - Investments - Amortized Cost (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Amortized cost
Amortized Cost	$ 75,500	$ 101,599
Gross Unrealized Gains	179	78
Gross Unrealized Losses	(8)	(16)
Estimated Fair Value	75,671	101,661
U.S. Government and agency securities
Amortized cost
Amortized Cost	32,066	30,742
Gross Unrealized Gains	108	38
Gross Unrealized Losses		(5)
Estimated Fair Value	32,174	30,775
Corporate debt securities
Amortized cost
Amortized Cost	42,129	69,552
Gross Unrealized Gains	71	40
Gross Unrealized Losses	(8)	(11)
Estimated Fair Value	42,192	69,581
Certificates of deposit
Amortized cost
Amortized Cost	1,305	1,305
Estimated Fair Value	$ 1,305	$ 1,305

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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