Available-for-Sale-Securities - Schedule of Available-for-Sale Securities Reconciliation (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Cost	$ 106,997	$ 30,750
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(73)	(13)
Estimated Fair Value	106,924	30,737
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Cost	59,937	8,406
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(61)	(7)
Estimated Fair Value	59,876	8,399
Money market funds
Debt Securities, Available-for-sale [Line Items]
Cost	18,044	7,591
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	18,044	7,591
Municipal debt securities
Debt Securities, Available-for-sale [Line Items]
Cost	29,016	14,753
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(12)	(6)
Estimated Fair Value	$ 29,004	$ 14,747

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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