Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2020

Fair Value Disclosures [Abstract]

Assets and Liabilities Measured at Fair Value

Assets and liabilities measured at fair value at each balance sheet date are as follows (in thousands):

	June 30, 2020
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	111,201	$	—	$	—	$	111,201
Short-term marketable securities:
U.S. government treasuries	333,212		—		—		333,212
Corporate debt securities	—		49,761		—		49,761
Commercial paper	—		29,424		—		29,424
Long-term marketable securities:
Corporate debt securities	—		7,229		—		7,229
Total	$	444,413	$	86,414	$	—	$	530,827
Liabilities:
Foreign currency derivative contracts	$	—	$	108	$	—	$	108
Total	$	—	$	108	$	—	$	108

	December 31, 2019
	Level 1		Level 2		Level 3		Total
Assets:
Cash equivalents:
Money market funds	$	54,163	$	—	$	—	$	54,163
U.S. government treasuries	15,989		—		—		15,989
Short-term marketable securities:
U.S. government treasuries	250,070		—		—		250,070
U.S. government agency securities	—		2,000		—		2,000
Corporate debt securities	—		53,479		—		53,479
Commercial paper	—		30,358		—		30,358
Long-term marketable securities:
U.S. government treasuries	13,869		—		—		13,869
Corporate debt securities	—		26,017		—		26,017
Foreign currency derivative contracts	—		85		—		85
Total	$	334,091	$	111,939	$	—	$	446,030
Liabilities:
Foreign currency derivative contracts	$	—	$	8	$	—	$	8
Total	$	—	$	8	$	—	$	8