Investments (Tables)

9 Months Ended

Sep. 30, 2021

Cash And Cash Equivalents [Abstract]

Schedule of Cash Equivalents

Cash equivalents and short-term investments consisted of the following as of September 30, 2021 and December 31, 2020 (in thousands):

	September 30, 2021				December 31, 2020
	Cost		Estimated Fair Value		Cost		Estimated Fair Value
Institutional money market funds	$	227,798	$	227,798	$	64,256	$	64,256
U.S. Treasury Bills		19,997		19,997		20,000		20,000
Total	$	247,795	$	247,795	$	84,256	$	84,256