Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2017

Summary of Fair Value Assets and Liabilities Measured on Recurring Basis

The following table sets 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 June 30, 2017
	Total		Level 1		Level 2		Level 3
Assets
Money market funds	$	116,328	$	116,328	$	—	$	—
U.S. government agency obligations		31,984		—		31,984		—
Corporate securities		16,013		—		16,013		—
Total	$	164,325	$	116,328	$	47,997	$	—

	Fair Value Measurements at December 31, 2016
	Total		Level 1		Level 2		Level 3
Assets
Money market funds	$	136,481	$	136,481	$	—	$	—
U.S. government agency obligations		12,075		—		12,075		—
Corporate securities		3,999		—		3,999		—
Total	$	152,555	$	136,481	$	16,074	$	—

Summary of Fair Value Measurement of Available-for-sale Securities

The following table is a summary of amortized cost, unrealized gain and loss, and fair value (in thousands) of the Company’s marketable securities by contractual maturities:

	Fair Value Measurements at June 30, 2017
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value
Cash equivalents (due within 90 days)	$	116,328	$	—	$	—		$	116,328
Short-term investments (due within one year)		16,031		—		(20	)	$	16,011
Long-term investments (due between one and two years)		32,011		6		(31	)	$	31,986
Total	$	164,370	$	6	$	(51	)	$	164,325

	Fair Value Measurements at December 31, 2016
	Amortized Cost		Unrealized Gain		Unrealized Loss			Fair Value
Cash equivalents (due within 90 days)	$	136,481	$	—	$	—		$	136,481
Short-term investments (due within one year)		4,072		—		—			4,072
Long-term investments (due between one and two years)		11,988		14		—			12,002
Total	$	152,541	$	14	$	—		$	152,555