Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis

The following table summarizes the Company's financial assets and liabilities measured at fair value on a recurring basis at March 31, 2018 and December 31, 2017 by level within the fair value hierarchy. Financial assets and financial liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement (in thousands):

	As of  March 31, 2018
	Quoted		Significant
	Prices in		Other		Significant
	Active		Observable		Unobservable
	Markets		Inputs		Inputs		Total Fair
	(Level 1)		(Level 2)		(Level 3)		Value
	(in thousands)
Assets:
Cash equivalents:
Money market funds	$	45,547		—		—	$	45,547
U.S. treasury securities		—		4,998				4,998
U.S. government and agency securities		—		9,191		—		9,191
Short-term investments:
U.S. treasury securities		—		27,959		—		27,959
U.S. government and agency securities		—		20,540		—		20,540
Total financial assets	$	45,547	$	62,688	$	—	$	108,235
Liabilities:
Contingent consideration		—		—	$	674	$	674
Total financial liabilities	$	—	$	—	$	674	$	674
	At December 31, 2017
	Quoted		Significant
	Prices in		Other		Significant
	Active		Observable		Unobservable
	Markets		Inputs		Inputs		Total Fair
	(Level 1)		(Level 2)		(Level 3)		Value
	(in thousands)
Assets:
Cash equivalents:
Money market funds	$	35,521		—		—	$	35,521
U.S. treasury securities		—		11,974				11,974
U.S. government and agency securities		—		50,352		—		50,352
Short-term investments:
U.S. treasury securities		—		12,972		—		12,972
U.S. government and agency securities		—		29,936		—		29,936
Total financial assets	$	35,521	$	105,234	$	—	$	140,755
Liabilities:
Contingent consideration		—		—	$	682	$	682
Total financial liabilities	$	—	$	—	$	682	$	682

Summary of Changes in Level 3 Financial Instruments

The following table summarizes the changes in Level 3 financial instruments (in thousands).

	Amount
Fair Value at December 31, 2017	$	682
Foreign currency translation		(8	)
Payments made during the year		—
Balance at March 31, 2018	$	674