Short-Term Investments (Tables)

12 Months Ended

Dec. 31, 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 December 31, 2021
	Amortized Cost		Unrealized Loss, Net			Estimated Fair Value
Government securities	$	134,980	$	(9	)	$	134,971
	As of December 31, 2020
	Amortized Cost		Unrealized Loss, Net			Estimated Fair Value
Government securities	$	54,983	$	(2	)	$	54,981