Investments (Tables)

12 Months Ended

Dec. 31, 2014

Investments

Summary of the Company's cash equivalents and investments

	December 31, 2014
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(in thousands)
Cash equivalents:
Money market funds	$	357	$	—	$	—		$	357
Short-term investments:
Certificates of deposit		2,934		—		—			2,934
U.S treasury notes		9,020		4		—			9,024
U.S. government agency securities		8,853		—		(8	)		8,845
Long-term investments:
Certificates of deposit		1,848		—		—			1,848
U.S. treasury notes		2,494		—		(5	)		2,489
U.S. government agency securities		31,454		—		(50	)		31,404
Total	$	56,960	$	4	$	(63	)	$	56,901

	December 31, 2013
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(in thousands)
Cash equivalents:
Money market funds	$	5,356	$	—	$	—		$	5,356
Short-term investments:
U.S treasury notes		2,071		—		—			2,071
U.S. government agency securities		1,454		—		—			1,454
Long-term investments:
Certificates of deposit		238		—		—			238
U.S. treasury notes		9,116		3		(2	)		9,117
U.S. government agency securities		8,187		1		(5	)		8,183
Total	$	26,422	$	4	$	(7	)	$	26,419