Investments (Tables)

3 Months Ended

Mar. 31, 2014

Investments

Summary of Short-term investments

Short-term investments as of December 31, 2013 are summarized as follows:

	Amortized Cost		Gross Unrealized Losses			Estimated Fair Value
Municipal bonds & notes	$	60,047	$	(252	)	$	59,795
Corporate bonds	43,166		(342		)	42,824
Certificate of deposits	35,630		(9		)	35,621
	$	138,843	$	(603	)	$	138,240

Short-term investments as of March 31, 2014 are summarized as follows:

	Amortized Cost		Gross Unrealized Losses			Estimated Fair Value
Municipal bonds & notes	$	67,309	$	(376	)	$	66,933
Corporate bonds	62,364		(537		)	61,827
Certificate of deposits	35,728		(6		)	35,722
	$	165,401	$	(919	)	$	164,482