Marketable Investments

9 Months Ended

Sep. 30, 2011

Marketable Investments

Marketable Investments

5. Marketable Investments

Held-to-Maturity Investments

Marketable investments classified as held-to-maturity consist of the following (in thousands):

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Government-sponsored enterprises at September 30, 2011	$	262,937	$	117	$	(112	)	$	262,942
Corporate notes and bonds at September 30, 2011	337,389		84		(497		)	336,976
Total	$	600,326	$	201	$	(609	)	$	599,918
Reported under the following captions on the consolidated balance sheet at September 30, 2011:
Current marketable securities	$	350,614
Noncurrent marketable securities	249,712
	$	600,326

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Government-sponsored enterprises at December 31, 2010	$	282,005	$	52	$	(152	)	$	281,905
Corporate notes and bonds at December 31, 2010	225,394		144		(68		)	225,470
Total	$	507,399	$	196	$	(220	)	$	507,375
Reported under the following captions on the consolidated balance sheet at December 31, 2010:
Current marketable securities	$	374,921
Noncurrent marketable securities	132,478
	$	507,399

The following table summarizes gross unrealized losses and the length of time marketable investments have been in a continuous unrealized loss position (in thousands):

	As of September 30, 2011					As of December 31, 2010
	Fair Value		Gross Unrealized Loss			Fair Value		Gross Unrealized Loss
Government-sponsored enterprises:
Continuous unrealized loss position less than one year	$	154,319	$	(112	)	$	152,844	$	(152	)
Continuous unrealized loss position greater than one year	—		—			—		—
	154,319		(112		)	152,844		(152		)
Corporate notes and bonds:
Continuous unrealized loss position less than one year	$	183,766	$	(497	)	$	107,883	$	(68	)
Continuous unrealized loss position greater than one year	—		—			—		—
	183,766		(497		)	107,883		(68		)
Total	$	338,085	$	(609	)	$	260,727	$	(220	)

We attribute the unrealized losses on held-to-maturity securities as of September 30, 2011, to the variability in related market interest rates. We do not intend to sell these securities, nor is it more likely than not that we will be required to sell them prior to the end of their contractual term. Furthermore, we believe these securities do not expose us to undue market risk or counterparty credit risk. As such, we do not consider these securities to be other than temporarily impaired.

The following table summarizes the contractual maturities of held-to-maturity marketable investments at September 30, 2011 (in thousands):

	September 30, 2011
	Amortized Cost		Fair Value
Due in less than one year	$	350,614	$	350,627
Due in one to two years	249,712		249,291
Due in three to five years	—		—
Due after five years	—		—
Total	$	600,326	$	599,918

Equity Investments

We own less than 1 percent of the common stock of a publicly-traded company. Our investment in this company is classified as available-for-sale and reported at fair value based on the quoted market price.

We have equity investments totaling $8.0 million in privately-held corporations. We account for these investments at cost. The fair value of our investments has not been estimated as of September 30, 2011, as there have been no events or developments indicating that these investments may be impaired.  We include these investments within non-current other assets on our consolidated balance sheets.