Short-Term Investments (Tables)

9 Months Ended

Sep. 30, 2014

Investments, Debt and Equity Securities [Abstract]

Summary of short-term investments

The following is a summary of short-term investments held as of September 30, 2014:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
	(in thousands)
Corporate debt	$	184,141	$	91	$	(193	)	$	184,039
U.S. government and agency debt	23,797		11		(2		)	23,806
Municipal bonds	22,924		7		(4		)	22,927
Other fixed income securities	22,533		—		(5		)	22,528
Total short-term investments	$	253,395	$	109	$	(204	)	$	253,300

Schedule of contractual maturities of short-term investments

Contractual maturities of short-term investments as of September 30, 2014 are shown below. 

	Under 1 Year		1 to 5 Years		Total
	(in thousands)
Corporate debt	$	80,081	$	103,958	$	184,039
U.S. government and agency debt	16,325		7,481		23,806
Municipal bonds	8,244		14,683		22,927
Other fixed income securities	22,528		—		22,528
Total short-term investments	$	127,178	$	126,122	$	253,300