Short-Term Investment (Tables)

9 Months Ended

Sep. 30, 2021

Short Term Investments [Abstract]

Schedule of Short-term Investments Available For Sale

Short-term investments, principally U.S. Treasury bills, are available-for-sale and consisted of the following (in thousands):

	As of September 30, 2021
	Amortized Cost		Unrealized Loss, Net			Estimated Fair Value
Government securities	$	99,989	$	(4	)	$	99,985

	As of December 31, 2020
	Amortized Cost		Unrealized Loss, Net			Estimated Fair Value
Government securities	$	54,983	$	(2	)	$	54,981