Note 3 - Investment Securities

3 Months Ended

Mar. 31, 2013

Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block]

Note 3 — Investment Securities

The Company’s investments in marketable securities are classified as available-for-sale and are reported at fair market value with the net unrealized gain or (loss) reported as a component of accumulated other comprehensive income (loss) in stockholders’ equity. Investment securities are classified as cash equivalents, short-term investments and long-term investments based on maturity date. Cash equivalents have maturities of three months or less, short-term investments have maturities of greater than three months but equal to or less than one year and long-term investments are those with a maturity date greater than one year. As of March 31, 2013, all of the Company’s long-term investments had contractual maturities of less than 18 months. Investment securities consisted of the following:

	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

The amortized cost of investment securities sold is determined by the specific identification method with any realized gains or losses reflected in other (income) expense. The Company had no realized gains or losses during the three months ended March 31, 2013 or 2012.

The Company believes unrealized losses related to debt securities are not other-than-temporary.