3. Investments

We do not intend to sell and we do not believe that it is more likely than not that we will be required to sell our investments before recovering the cost of securities, nor do we expect not to recover the entire amortized cost basis of our investments in marketable securities. As such, our investments in marketable securities as of December 31, 2011 and 2010 are classified as held-to-maturity and are carried at cost plus accrued interest. The changes in the value of these securities, other than impairment charges, are not reported on our financial statements. The weighted average duration of the remaining time to maturity for our portfolio of investments in marketable securities as of December 31, 2011 was less than one month. All of the investments classified as short-term on the balance sheet have an original maturity of longer than 90 days, but less than one year. The

investments classified as long-term on the balance sheet have remaining contractual maturities of greater than one year and less than three years as of the balance sheet date.

The carrying value of investments in marketable securities by contractual maturity, consisted of the following as of December 31, 2011:


					Gross		Gross
		Amortized			Unrealized		Unrealized		Fair
		cost			Gains		Losses		Value
Short-term held-to-maturity securities:
U.S. Treasury notes	$	10,051		$	—	$	-	$	10,051
Certificate of deposit		280			-		-		280
Corporate note		307			1		-		308
Sub-total	$	10,638		$	1	$	-	$	10,639
Less: Amounts classified as restricted cash		(238	)		—		—		(238	)
Total due in one year or less	$	10,400		$	1	$	-	$	10,401

The carrying value of investments in marketable securities by contractual maturity, consisted of the following as of December 31, 2010:


					Gross		Gross
		Amortized			Unrealized		Unrealized		Fair
		cost			Gains		Losses		Value
Short-term held-to-maturity securities:
U.S. Treasury bills and notes	$	50,063		$	11	$	1	$	50,073
U.S. Government agency securities		271			6		—		277
Total due in one year or less	$	50,334		$	17	$	1	$	50,350

Long-term held-to-maturity securities:
Corporate notes	$	305		$	11	$	—	$	316
Less: Amounts classified as restricted cash		(238	)		—		—		(238	)
Total due in one to two years	$	67		$	11	$	—	$	78

As of December 31, 2011 and 2010 there were no material investments in a loss position. Market values were determined for each individual security in the investment portfolio. If a decline in fair value below the amortized cost basis of an investment is judged to be other-than-temporary, the cost basis of the investment is written down to fair value. Additionally, management assesses whether it intends to sell or would more-likely-than-not not be required to sell the investment before the expected recovery of the amortized cost basis. During the year ended December 31, 2009, we realized losses of approximately $157,000 on the sale of certain of our investments in marketable securities, which were sold in order to preserve our principal as the issuers of these securities experienced significant deteriorations in their creditworthiness as evidenced by investment rating downgrades. As of December 31, 2011, there were no investments in a material unrealized loss position. We have the ability and intent to hold our remaining investments in marketable securities to recover the entire amortized cost basis of the investments as of December 31, 2011. As of December 31, 2010, we had an unrealized loss of $1,000 on one of our U.S. Treasury bill investments with an aggregate fair value of $10.0 million.