Note 5 - Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2012

Investment [Table Text Block]

	Cost			Gross Unrealized Gains			Gross Unrealized Losses			Estimated Fair Value
	(in thousands)
Available-for-sale securities:
Short-term deposits	$	44,592		$	-		$	-		$	44,592
Mutual funds		10,000			135			-			10,135
United States government securities		117,794			253			(7	)		118,040
Government agencies		2,501			3			-			2,504
Corporate securities		4,720			43			(208	)		4,555
Commercial paper		35,805			21			-			35,826
Corporate obligations		33,842			9			(12	)		33,839
Total available-for-sale securities		249,254			464			(227	)		249,491
Amounts classified as cash equivalents		(61,284	)		(1	)		1			(61,284	)
Amounts classified as marketable securities	$	187,970		$	463		$	(226	)	$	188,207

	Cost			Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(in thousands)
Available-for-sale securities:
Short-term deposits	$	3,029		$	-	$	-		$	3,029
United States government securities		309,189			593		(3	)		309,779
Government agencies		3,505			21		-			3,526
Corporate obligations		1,513			8		-			1,521
Total available-for-sale securities		317,236			622		(3	)		317,855
Amounts classified as cash equivalents		(2,914	)		-		-			(2,914	)
Amounts classified as marketable securities	$	314,322		$	622	$	(3	)	$	314,941

Schedule of Unrealized Loss on Investments [Table Text Block]

	Less than 12 Months					12 Months or Greater				Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
	(in thousands)
U.S. government securities	$	64,129	$	(7	)	$	-	$	-	$	64,129	$	(7	)
Corporate securities		3,631		(208	)		-		-		3,631		(208	)
Corporate obligations		18,461		(13	)		-		-		18,461		(13	)
Total	$	86,221	$	(228	)	$	-	$	-	$	86,221	$	(228	)

	Less than 12 Months					12 Months or Greater				Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
	(in thousands)
U.S. government securities	$	15,186	$	(3	)	$	-	$	-	$	15,186	$	(3	)

Investments Classified by Contractual Maturity Date [Table Text Block]

	June 30, 2012				December 31, 2011
	Cost		Estimated Fair Value		Cost		Estimated Fair Value
	(in thousands)
Mature in one year or less	$	229,591	$	229,664	$	256,764	$	257,050
Mature after one year through three years		19,645		19,809		60,473		60,805
Total	$	249,236	$	249,473	$	317,237	$	317,855