Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2019

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets Measured on Recurring Basis

The following tables set forth the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):

	Fair Value Measurements at September 30, 2019
	Total		Level 1		Level 2		Level 3
Assets
Money market funds	$	64,611	$	64,611	$	—	$	—
Corporate securities and commercial paper		51,630		—		51,630		—
U.S. government treasury and agency securities		80,740		—		80,740		—
	$	196,981	$	64,611	$	132,370	$	—

	Fair Value Measurements at December 31, 2018
	Total		Level 1		Level 2		Level 3
Assets
Money market funds	$	45,017	$	45,017	$	—	$	—
U.S. government treasury and agency securities		103,940		—		103,940		—
Corporate securities and commercial paper		110,768		—		110,768		—
	$	259,725	$	45,017	$	214,708	$	—

Schedule of Investments Classified as Available for Sale Securities with Contractual Maturities

Classified as (with contractual maturities):

	September 30, 2019		December 31, 2018
Cash and Cash equivalents	$	78,992	$	71,064
Short-term investments (due within one year)		111,997		185,480
Long-term investments (due between one and two years)		5,992		3,181
	$	196,981	$	259,725

Schedule of Available for Sale Securities at Fair Value Measurements

	Fair Value Measurements at September 30, 2019
	Amortized Cost		Unrealized Gain		Unrealized Loss		Fair Value
Money market funds	$	64,611	$	—	$	—	$	64,611
Corporate securities and commercial paper		51,618		12		—		51,630
U.S. government treasury and agency securities		80,698		42		—		80,740
	$	196,927	$	54	$	—	$	196,981

	Fair Value Measurements at December 31, 2018
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value
Money market funds	$	45,017	$	—	$	—		$	45,017
U.S. government treasury and agency securities		103,957		—		(17	)		103,940
Corporate securities and commercial paper		110,859		—		(91	)		110,768
	$	259,833	$	—	$	(108	)	$	259,725