Note 6 - Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2013

Investment [Table Text Block]

	Cost			Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(in thousands)
Available-for-sale securities:
Short-term deposits	$	47,490		$	-	$	-		$	47,490
Mutual funds		10,368			2,724		-			13,092
United States government securities		78,346			131		-			78,477
Corporate securities		30,387			2,829		(686	)		32,530
Corporate obligations		54,373			1,029		(472	)		54,930
Commercial paper		21,541			5		-			21,546
Total available-for-sale securities		242,505			6,718		(1,158	)		248,065
Amounts classified as cash equivalents		(61,727	)		-		-			(61,727	)
Amounts classified as marketable securities	$	180,778		$	6,718	$	(1,158	)	$	186,338

	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
Commercial 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

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	$	1,408	$	-	$	-	$	-	$	1,408	$	-
Corporate oligations		5,406		2		6,536		470		11,942		472
Total	$	6,814	$	2	$	6,536	$	470	$	13,350	$	472

	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	)

Investments Classified by Contractual Maturity Date [Table Text Block]

	Cost		Estimated  Fair Value
	(in thousands)
Mature in one year or less	$	214,006	$	219,000
Mature after one year through three years		7,998		8,415
Mature in more than three years		20,501		20,650
Total	$	242,505	$	248,065