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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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The Company and a Summary of its Significant Accounting Policies - Summary of Assets Measured at Fair Value on Recurring Basis (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Marketable securities, available for sale:
Marketable securities, available for sale	$ 36,761,000
Fair Value, Recurring
Assets:
Cash equivalents	3,077,000
Marketable securities, available for sale:
Marketable securities, available for sale	36,907,000
Total assets measured at fair value on a recurring basis	39,984,000	$ 0
Fair Value, Recurring \| Level 1
Assets:
Cash equivalents	3,077,000
Marketable securities, available for sale:
Total assets measured at fair value on a recurring basis	3,077,000
Fair Value, Recurring \| Level 2
Marketable securities, available for sale:
Marketable securities, available for sale	36,907,000
Total assets measured at fair value on a recurring basis	36,907,000
Corporate Debt
Marketable securities, available for sale:
Marketable securities, available for sale	7,909,000
Corporate Debt \| Fair Value, Recurring
Marketable securities, available for sale:
Marketable securities, available for sale	7,960,000
Corporate Debt \| Fair Value, Recurring \| Level 2
Marketable securities, available for sale:
Marketable securities, available for sale	7,960,000
Municipal Securities
Marketable securities, available for sale:
Marketable securities, available for sale	6,798,000
Municipal Securities \| Fair Value, Recurring
Marketable securities, available for sale:
Marketable securities, available for sale	6,804,000
Municipal Securities \| Fair Value, Recurring \| Level 2
Marketable securities, available for sale:
Marketable securities, available for sale	6,804,000
U.S. Government Debt Securities
Marketable securities, available for sale:
Marketable securities, available for sale	22,054,000
U.S. Government Debt Securities \| Fair Value, Recurring
Marketable securities, available for sale:
Marketable securities, available for sale	22,143,000
U.S. Government Debt Securities \| Fair Value, Recurring \| Level 2
Marketable securities, available for sale:
Marketable securities, available for sale	$ 22,143,000