INVESTMENTS (Tables)

12 Months Ended

Dec. 31, 2011

Available-For-Sale Securities

The following is a summary of our available-for-sale securities at December 31, 2011:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(In thousands)
Mutual funds	$	1,975	$	—	$	(52	)	$	1,923
Commercial paper		123,195		22		(7	)		123,210
Asset-backed securities and collateralized mortgage obligations(1)		12,489		—		(4,358	)		8,131
Corporate notes and bonds		5,750		—		(8	)		5,742
Total	$	143,409	$	22	$	(4,425	)	$	139,006

(1) Included in our asset-backed securities and collateralized mortgage obligations is approximately $7.4 million of commercial paper secured by mortgaged-backed securities.

The following is a summary of our available-for-sale securities at December 31, 2010:

	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(In thousands)
U.S. Treasury securities and obligations of U.S. Government agencies	$	269,154	$	8	$	(1	)	$	269,161
Money market instruments and short-term investments		1,975		32		—			2,007
Asset-backed securities and collateralized mortgage obligations(1)		14,248		—		(4,379	)		9,869
Corporate and foreign government bonds and notes		4,167		1		—			4,168
Total	$	289,544	$	41	$	(4,380	)	$	285,205

Proceeds, Gross Realized Gains and Gross Realized Losses on Sales of Available-For-Sale Securities

Proceeds, gross realized gains and gross realized losses on sales of available-for-sale securities were as follows:

	Proceeds		Gross Realized Gains		Gross Realized Losses
	(In thousands)
Year Ended December 31, 2011	$	693,424	$	—	$	20
Year Ended December 31, 2010	$	1,363,803	$	—	$	91
Year Ended December 31, 2009	$	331,474	$	—	$	94