Marketable Securities - Summary of Marketable Securities (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 6,684,000
Unrealized Gains	0
Unrealized Losses	(5,000)
Marketable securities:	6,679,000	$ 0
Corporate Debt Securities with 1 Year or Less Maturity
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	3,612,000
Unrealized Gains	0
Unrealized Losses	(2,000)
Marketable securities:	3,610,000
Corporate Debt Securities with 1 to 2 Years Maturity
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	3,072,000
Unrealized Gains	0
Unrealized Losses	(3,000)
Marketable securities:	$ 3,069,000

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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