Note 6 Cash and Cash Equivalents and Short-term Investments

Our cash and cash equivalents and short-term investments consisted of the following:

	December 31,
	2012		2011
	(In thousands)
Cash and cash equivalents	$	524,922	$	398,575
Short-term investments:
Trading equity securities	$	52,705	$	11,600
Available-for-sale equity securities	174,610		71,433
Available-for-sale debt securities	25,967		57,881
Total short-term investments	$	253,282	$	140,914

Certain information related to our cash and cash equivalents and short-term investments follows:

	December 31,
	2012							2011
	Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Fair Value		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses
	(In thousands)
Cash and cash equivalents	$	524,922	$	—	$	—		$	398,575	$	—	$	—
Short-term investments:
Trading equity securities	52,705		46,981		—			11,600		5,876		—
Available-for-sale equity securities	174,610		137,282		(1,030		)	71,433		33,075		—
Available-for-sale debt securities:
Commercial paper and CDs	206		—		—			1,230		—		—
Corporate debt securities	23,399		1,870		—			51,300		22,494		(2,095		)
Mortgage-backed debt securities	244		15		—			309		10		—
Mortgage-CMO debt securities	523		10		(3		)	2,547		13		(15		)
Asset-backed debt securities	1,595		28		(192		)	2,495		—		(238		)
Total available-for-sale debt securities	25,967		1,923		(195		)	57,881		22,517		(2,348		)
Total available-for-sale securities	200,577		139,205		(1,225		)	129,314		55,592		(2,348		)
Total short-term investments	253,282		186,186		(1,225		)	140,914		61,468		(2,348		)
Total cash, cash equivalents and short-term investments	$	778,204	$	186,186	$	(1,225	)	$	539,489	$	61,468	$	(2,348	)

Certain information related to the gross unrealized losses of our cash and cash equivalents and short-term investments follows:

	As of December 31, 2012
	Less Than 12 Months				More Than 12 Months
	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
	(In thousands)
Available-for-sale equity securities	$	17,865	$	1,030	$	—	$	—
Available-for-sale debt securities: (1)
Corporate debt securities	—		—		—		—
Mortgage-CMO debt securities	315		1		35		2
Asset-backed debt securities	—		—		500		192
Total available-for-sale debt securities	315		1		535		194
Total	$	18,180	$	1,031	$	535	$	194

(1) Our unrealized losses on available-for-sale debt securities held for more than one year are comprised of various types of securities. Each of these securities have a rating ranging from “A” to “AAA” from Standard & Poor’s and ranging from “A2” to “Aaa” from Moody’s Investors Service and is considered of high credit quality. In each case, we do not intend to sell these investments, and it is less likely than not that we will be required to sell them to satisfy our own cash flow and working capital requirements. We believe that we will be able to collect all amounts due according to the contractual terms of each investment and, therefore, do not consider the decline in value of these investments to be other-than-temporary at December 31, 2012.

The estimated fair values of our corporate, mortgage-backed, mortgage-CMO and asset-backed debt securities at December 31, 2012, classified by time to contractual maturity, are shown below. Expected maturities differ from contractual maturities because the issuers of the securities may have the right to repay obligations without prepayment penalties and we may elect to sell the securities prior to the contractual maturity date.

	Estimated
	Fair Value
	December 31, 2012
	(In thousands)
Debt securities:
Due in one year or less	$	206
Due after one year through five years	19,225
Due in more than five years	6,536
Total debt securities	$	25,967

Certain information regarding our debt and equity securities is presented below:

	Year Ended December 31,
	2012		2011		2010
	(In thousands)
Available-for-sale
Proceeds from sales and maturities	$	24,010	$	12,672	$	13,062
Realized gains (losses), net	$	13,405	$	3,036	$	1,694