Note 3 - Investment Securities (Tables)

3 Months Ended

Mar. 31, 2013

Unrealized Gain (Loss) on Investments [Table Text Block]

	As of March 31, 2013									As of December 31, 2012
			Gross Unrealized									Gross Unrealized
	Cost		Gains		(Losses)			Market Value		Cost		Gains		(Losses)			Market Value
Money market funds	$	51,210	$	-	$	-		$	51,210	$	3,689	$	-	$	-		$	3,689
Certificates of deposit		-		-		-			-		5,862		1		-			5,863
Commercial paper		157,733		13		(56	)		157,690		82,163		16		(42	)		82,137
Municipal debt securities		154,051		14		(16	)		154,049		190,507		-		(33	)		190,474
Government debt securities		23,015		1		(2	)		23,014		22,011		2		-			22,013
Corporate debt securities		22,513		40		(11	)		22,542		33,310		-		(13	)		33,297
Total	$	408,522	$	68	$	(85	)	$	408,505	$	337,542	$	19	$	(88	)	$	337,473