Short-term Investments (Tables)

6 Months Ended

Jun. 30, 2015

Short-term Investments [Abstract]

Short-term Investments Measured at Fair Value

As of June 30, 2015, the fair value of the Company’s short-term investments was as follows (in thousands):

	June 30, 2015
	Amortized cost		Unrealized gains		Unrealized loss		Fair value
	(unaudited)
U.S. agency notes	$	36,617	$	4	$	(3)	$	36,618
Corporate bonds		36,998		1		(31)		36,968
Commercial paper		24,794		2		—		24,796
Marketable securities		98,409		7		(34)		98,382
Certificates of deposit		7,000		—		—		7,000
Total short-term investments	$	105,409	$	7	$	(34)	$	105,382

As of December 31, 2014, the fair value of the Company’s short-term investments was as follows (in thousands):

		December 31, 2014
	Amortized cost		Unrealized gains		Unrealized loss		Fair value
U.S. agency notes	$	33,489	$	—	$	(13)	$	33,476
Corporate bonds		44,025		3		(44)		43,984
Commercial paper		31,318		—		(1)		31,317
Marketable securities		108,832		3		(58)		108,777
Certificates of deposit		3,000		—		—		3,000
Total short-term investments	$	111,832	$	3	$	(58)	$	111,777