Marketable Securities (Tables)

6 Months Ended

Jun. 30, 2013

Investments, Debt and Equity Securities [Abstract]

Available-for-sale Securities [Table Text Block]

The amortized cost, gross unrealized holding gains or losses, and fair value of the Company’s marketable securities by major security type at June 30, 2013 were as follows (in thousands):

	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Fair Value*
Corporate bonds	$	3,004		-	$	(3)	$	3,001
	$	3,004		-	$	(3)	$	3,001

* Included in current marketable securities at June 30, 2013.

 The amortized cost, gross unrealized holding gains or losses, and fair value of the Company’s marketable securities by major security type at December 31, 2012 were as follows (in thousands):

	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses		Fair Value*
Corporate bonds	$	86,769	$	82	$	(11)	$	86,840
Commercial paper		30,482		8		-		30,490
U.S. government-sponsored agency		2,057		4		-		2,061
	$	119,308	$	94	$	(11)	$	119,391

* Included in current marketable securities at December 31, 2012.

Investments Classified by Contractual Maturity Date [Table Text Block]

Maturities of marketable debt securities, based on contractual maturity, at June 30, 2013 were as follows (in thousands):

	Amortized Cost		Fair Value
Due in one year or less	$	3,004	$	3,001
	$	3,004	$	3,001