Investments (Tables)

3 Months Ended

Mar. 31, 2020

Investments, Debt and Equity Securities [Abstract]

Short-term investments available-for-sale

Our investments are classified as available-for-sale and consist of the following:

	March 31, 2020
			Unrealized
	Cost		Gains		Losses		Fair Value
Short-Term:
Commercial paper	$	6,292	$	—	$	—	$	6,292
Asset-backed securities	6,100		1		(7)		6,094
U.S. government securities	47,021		201		—		47,222
Short-term investments	$	59,413	$	202	$	(7)	$	59,608
Long-Term:
U.S. government securities	6,047		92		—		6,139
Long-term investments	$	6,047	$	92	$	—	$	6,139

	December 31, 2019
			Unrealized
	Cost		Gains		Losses		Fair Value
Short-Term:
Commercial paper	$	14,214	$	—	$	—	$	14,214
Corporate bonds	26,194		16		(2)		26,208
Asset-backed securities	8,097		5		(1)		8,101
U.S. government securities	78,017		65		—		78,082
Short-term investments	$	126,522	$	86	$	(3)	$	126,605
Long-Term:
Corporate bonds	6,258		18		—		6,276
Long-term investments	$	6,258	$	18	$	—	$	6,276