Fair Value Measurement (Tables)

3 Months Ended

Mar. 31, 2017

Fair Value Disclosures [Abstract]

Schedule of Financial Instruments Measured at Fair Value (in thousands)

	As of March 31, 2017
(in thousands)	Level 1		Level 2		Level 3		Total
Money market funds	$	15,633	$	—	$	—	$	15,633
Corporate debt securities		—		6,620		—		6,620
Commercial paper		—		51,137		—		51,137
Total	$	15,633	$	57,757	$	—	$	73,390

	As of December 31, 2016
(in thousands)	Level 1		Level 2		Level 3		Total
Money market funds	$	15,003	$	—	$	—	$	15,003
Corporate debt securities		—		10,738		—		10,738
Commercial paper		—		47,479		—		47,479
Total	$	15,003	$	58,217	$	—	$	73,220