3. Cash, cash equivalents and marketable securities

The following is a summary of cash, cash equivalents and marketable securities available-for-sale as of June 30, 2015 and December 31, 2014 (in thousands):

	Amortized Cost		Unrealized Gains		Unrealized Losses			Estimated Fair Value
June 30, 2015
Cash and cash equivalents:
Cash	$	5,639	$	-	$	-		$	5,639
Money market funds		30,847		-		-			30,847
Total cash and cash equivalents		36,486		-		-			36,486
Marketable securities available-for-sale:
U.S. government agency securities		56,895		7		(7	)		56,895
Total marketable securities available-for-sale		56,895		7		(7	)		56,895
Total cash, cash equivalents and marketable securities	$	93,381	$	7	$	(7	)	$	93,381
December 31, 2014
Cash and cash equivalents:
Cash	$	2,522	$	-	$	-		$	2,522
Money market funds		46,989		-		-			46,989
Total cash and cash equivalents		49,511		-		-			49,511
Marketable securities available-for-sale:
U.S. government agency securities		73,140		11		(10	)		73,141
Total marketable securities available-for-sale		73,140		11		(10	)		73,141
Total cash, cash equivalents and marketable securities	$	122,651	$	11	$	(10	)	$	122,652

The maturities of our marketable securities available-for-sale are as follows (in thousands):

	June 30, 2015
	Amortized Cost		Estimated Fair Value
Mature in one year or less	$	56,895	$	56,895
Mature after one year through two years		-		-
	$	56,895	$	56,895

All of our investments are classified as short-term and available-for-sale, as we may not hold our investments until maturity. Available-for-sale securities are carried at fair value based on inputs that are observable, either directly or indirectly, such as quoted market prices for similar securities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the securities, with unrealized gains and losses included in accumulated other comprehensive income (loss) in stockholders’ equity. Realized gains and losses and declines in value, if any, judged to be other than temporary on available-for-sale securities are included in interest income or expense. The cost of securities sold is based on the specific identification method. Management assesses whether declines in the fair value of investment securities are other than temporary. In determining whether a decline is other than temporary, management considers the following factors:

·	Whether the investment has been in a continuous realized loss position for over 12 months;

·	the duration to maturity of our investments;

·	our intention and ability to hold the investments to maturity and if it is not more likely than not that we will be required to sell the investment before recovery of the amortized cost bases;

·	the credit rating, financial condition and near-term prospects of the issuer; and

·	the type of investments made.

To date, there have been no declines in fair value that have been identified as other than temporary.