Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2015

Fair Value Disclosures [Abstract]

Summary of Fair Value of Financial Assets and Liabilities that are Measured at Fair Value and the Classification by Level of Input within Fair Value Hierarchy

The following tables summarize the fair value of financial assets and liabilities that are measured at fair value and the classification by level of input within the fair value hierarchy:

	FAIR VALUE MEASUREMENTS AS OF MARCH 31, 2015
(in thousands)	Level 1		Level 2		Level 3		Total
Cash and cash equivalents:
Cash and money market accounts	$	113,450	$	—	$	—	$	113,450
Total cash and cash equivalents	$	113,450	$	—	$	—	$	113,450
Investments:
Certificates of deposit	$	—	$	29,246	$	—	$	29,246
Commercial paper	—		5,993		—		5,993
Corporate bonds	—		24,568		—		24,568
Government agencies	—		6,053		—		6,053
Total investments	$	—	$	65,860	$	—	$	65,860
Total cash, cash equivalents, and investments	$	113,450	$	65,860	$	—	$	179,310

	FAIR VALUE MEASUREMENTS AS OF DECEMBER 31, 2014
(in thousands)	Level 1		Level 2		Level 3		Total
Cash and cash equivalents:
Cash and money market accounts	$	84,613	$	—	$	—	$	84,613
Certificates of deposit	—		472		—		472
Corporate bonds	—		501		—		501
Total cash and cash equivalents	$	84,613	$	973	$	—	$	85,586
Investments:
Certificates of deposit	$	—	$	30,241	$	—	$	30,241
Commercial paper	—		5,986		—		5,986
Corporate bonds	—		30,311		—		30,311
Government agencies	—		6,076		—		6,076
Total investments	$	—	$	72,614	$	—	$	72,614
Total cash, cash equivalents, and investments	$	84,613	$	73,587	$	—	$	158,200