Fair Value of Financial Instruments (Tables)

12 Months Ended

Dec. 31, 2014

Fair Value of Financial Instruments

Schedule of fair value of financial assets and liabilities measured at fair value and classification by level of input

	Fair Value Measurements as of
	December 31, 2014
(in thousands)	Level 1		Level 2		Level 3		Total
Investments:
Money market funds	$	9,663	$	—	$	—	$	9,663
Federal agency securities		—		13,770		—		13,770
Commercial paper		—		1,500		—		1,500
Corporate debt securities		—		14,520		—		14,520
Total assets measured at fair value	$	9,663	$	29,790		—	$	39,453
Financing derivative		—		—		89		89
Total liabilities measured at fair value	$	—	$	—	$	89	$	89

	Fair Value Measurements as of
	December 31, 2013
(in thousands)	Level 1		Level 2		Level 3		Total
Investments:
Money market funds	$	53,511	$	—	$	—	$	53,511
Federal agency securities		—		12,301		—		12,301
Commercial paper		—		8,249		—		8,249
Corporate debt securities		—		1,961		—		1,961
Total assets measured at fair value	$	53,511	$	22,511	$	—	$	76,022