Short-term Investments (Tables)

12 Months Ended

Dec. 31, 2014

Summary Of Investments In Available-For-Sale Securities

The following table summarizes the Company’s investments in available-for-sale securities as of December 31, 2014 and 2013 (in thousands):



	December 31, 2014
			Unrealized
	Amortized Cost		Gains		Losses			Estimated Fair Value
Municipal bonds	$	120,270	$	24	$	(12	)	$	120,282
Commercial paper	2,498		—		—			2,498
Corporate bonds	68,758		1		(87		)	68,672
U.S. government and agency securities	48,095		—		(33		)	48,062
	$	239,621	$	25	$	(132	)	$	239,514



	December 31, 2013
			Unrealized
	Amortized Cost		Gains		Losses			Estimated Fair Value
Municipal bonds	$	146,047	$	56	$	(3	)	$	146,100
Commercial paper	31,597		—		—			31,597
Corporate bonds	7,873		2		—			7,875
U.S. government and agency securities	5,002		—		(7		)	4,995
	$	190,519	$	58	$	(10	)	$	190,567

- Definition

Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities.

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