Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2020

Investments All Other Investments [Abstract]

Cash Equivalents and Investments Classified as Available-for-Sale Securities

Cash equivalents and investments (debt securities) which are classified as available-for-sale debt securities, consisted of the following (in thousands):

September 30, 2020	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Money market funds (cash equivalents)	$	24,923	$	—	$	—	$	24,923
U.S. government agency securities		55,038		4		—		55,042
Federal agency securities		24,084		4		—		24,088
Total financial assets	$	104,045	$	8	$	—	$	104,053
Classified as:
Cash and cash equivalents							$	24,923
Short-term investments								77,959
Long-term investments								1,171
							$	104,053

December 31, 2019	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Money market funds (cash equivalents)	$	15,369	$	—	$	—	$	15,369
U.S. government agency securities		51,467		23		—		51,490
Federal agency securities		9,995		11		—		10,006
Total financial assets	$	76,831	$	34	$	—	$	76,865
Classified as:
Cash and cash equivalents							$	15,369
Short-term investments								61,496
							$	76,865