Marketable Investments

12 Months Ended

Dec. 31, 2012

Marketable Investments

Marketable Investments

4. Marketable Investments

• Held-to-Maturity Investments

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

	December 31, 2012
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Government-sponsored enterprises	$	350,043	$	261	$	(35	)	$	350,269
Corporate notes and bonds		280,385		184		(140	)		280,429
Total	$	630,428	$	445	$	(175	)	$	630,698
Reported under the following captions on the consolidated balance sheet:
Current marketable investments	$	325,175
Noncurrent marketable investments		305,253
	$	630,428

	December 31, 2011
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Government-sponsored enterprises	$	308,202	$	155	$	(170	)	$	308,187
Corporate notes and bonds		276,118		113		(442	)		275,789
Total	$	584,320	$	268	$	(612	)	$	583,976
Reported under the following captions on the consolidated balance sheet:
Current marketable investments	$	240,803
Noncurrent marketable investments		343,517
	$	584,320

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

	December 31,
	2012					2011
	Fair Value		Gross Unrealized Loss			Fair Value		Gross Unrealized Loss
Government-sponsored enterprises:
Less than one year	$	72,727	$	(35	)	$	170,018	$	(170	)
Greater than one year		—		—			—		—
		72,727		(35	)		170,018		(170	)
Corporate notes and bonds:
Less than one year		90,960		(140	)		149,383		(442	)
Greater than one year		—		—			—		—
		90,960		(140	)		149,383		(442	)
Total	$	163,687	$	(175	)	$	319,401	$	(612	)

        We attribute the unrealized losses on held-to-maturity securities as of December 31, 2012 and 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 subject us to undue market risk or counterparty credit risk. As such, we do not consider any of these securities to be other than temporarily impaired.

        The following table summarizes the contractual maturities of held-to-maturity marketable investments at December 31, 2012 (in thousands):

	December 31, 2012
	Amortized Cost		Fair Value
Due in less than one year	$	325,175	$	325,392
Due in one to two years		305,253		305,306
Due in three to five years		—		—
Due after five years		—		—
Total	$	630,428	$	630,698

• Trading Investments

        For the years ended December 31, 2012 and 2011, we had no trading investments. During the year ended December 31, 2010, we recognized trading gains of $6.9 million.

• Equity Investments

        As of December 31, 2012 and 2011, we owned less than one percent of the common stock of a public company. Our investment is classified as available-for-sale and is reported at fair value based on the quoted market price. We include this investment within non-current marketable investments on our consolidated balance sheets.

        As of December 31, 2012, we maintain equity investments totaling approximately $8.0 million in privately-held corporations. We account for these investments at cost since we do not have the ability to exercise significant influence on these corporations and their fair values are not readily determinable. The fair value of these investments has not been estimated at December 31, 2012, as there have been no events or developments indicating the related carrying amounts may be impaired. We include these investments within non-current other assets on our consolidated balance sheets.