Note 6 - Marketable Securities (Tables)

12 Months Ended

Dec. 31, 2012

Investment [Table Text Block]

	Cost			Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(in thousands)
Available-for-sale securities:
Short-term deposits	$	48,596		$	-	$	-		$	48,596
Mutual funds		10,368			1,452		-			11,820
United States government securities		99,299			178		-			99,477
Corporate securities		20,842			1,255		(1,980	)		20,117
Corporate obligations		48,708			283		(277	)		48,714
Commerical paper		22,275			16		-			22,291
Total available-for-sale securities		250,088			3,184		(2,257	)		251,015
Amounts classified as cash equivalents		(51,887	)		-		-			(51,887	)
Amounts classified as marketable securities	$	198,201		$	3,184	$	(2,257	)	$	199,128

	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

Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [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	$	88,420	$	-		$	11,056	$	-		$	99,476	$	-
Corporate oligations		24,346		(2	)		24,370		(272	)		48,716		(274	)
Total	$	112,766	$	(2	)	$	35,426	$	(272	)	$	148,192	$	(274	)

	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]

	Cost		Estimated Fair Value
	(in thousands)
Mature in one year or less	$	214,784	$	215,589
Mature after one year through three years		19,550		19,854
Mature in more than three years		15,753		15,572
Total	$	250,087	$	251,015