Cash and Cash Equivalents and Investments (Tables)

12 Months Ended

Dec. 31, 2019

Cash and Cash Equivalents and Investments [Abstract]

Schedule of Cash, Cash Equivalents and Short-term Investments

	As of December 31, 2019
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
			(in thousands)
Cash and cash equivalents	$	36,112	$	—	$	—	$	36,112
Securities maturing within one year:
U.S. treasury securities	235,463		94		(10)		235,547
Total short-term investments	$	235,463	$	94	$	(10)	$	235,547
Total cash and cash equivalents and investments	$	271,575	$	94	$	(10)	$	271,659

	As of December 31, 2018
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
			(in thousands)
Cash and cash equivalents	$	80,386	$	—	$	—	$	80,386
Securities maturing within one year:
U.S. treasury securities	73,983		—		(9)		73,974
Corporate debt securities	5,695		—		(3)		5,692
Total short-term investments	$	79,678	$	—	$	(12)	$	79,666
Total cash and cash equivalents and investments	$	160,064	$	—	$	(12)	$	160,052