Marketable Securities

9 Months Ended

Sep. 30, 2011

Marketable Securities [Abstract]

MARKETABLE SECURITIES

NOTE 5. MARKETABLE SECURITIES

Our investments with original maturities of more than three months at time of purchase are considered marketable securities available for sale.

The composition of our marketable securities is as follows (in thousands):

	September 30, 2011				December 31, 2010
	Cost		Fair Value		Cost		Fair Value
Commercial paper	$	1,349	$	1,349	$	—	$	—
Treasury bills		—		—		2,003		2,006
Certificates of deposit		6,998		6,985		3,126		3,126
Corporate bonds/notes		6,270		6,251		1,002		1,004
Agency bonds/notes		8,084		8,084		3,503		3,504
Total marketable securities	$	22,701	$	22,669	$	9,634	$	9,640

The maturities of our marketable securities available for sale as of September 30, 2011 are as follows:

	Earliest		Latest
Commercial paper	12/5/2011	to		12/16/2011
Certificates of deposit	10/14/2011	to		9/23/2013
Corporate bonds/notes	2/15/2012	to		12/17/2012
Agency bonds / notes	7/15/2012	to		11/2/2012

The value and liquidity of our marketable securities are affected by market conditions, the ability of the issuer to make principal and interest payments when due, and the functioning of the markets in which these securities are traded. Our current investments in marketable securities are expected to be liquidated during the next 18 months.

As of September 30, 2011, we do not believe any of the underlying issuers of our marketable securities are presently at risk of default.