Cash and Cash Equivalents and Investments

3 Months Ended

Mar. 31, 2014

Cash and Cash Equivalents and Investments [Abstract]

Cash and Cash Equivalents Disclosure

Cash and Cash Equivalents and Investments

The fair value of cash and cash equivalents and investments held at March 31, 2014 and December 31, 2013 are as follows:

	As of March 31, 2014
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(in thousands)
Cash and cash equivalents	$	46,517	$	—	$	—		$	46,517
Securities maturing within one year:
Certificates of deposit	552		—		—			552
U.S. treasury securities	51,288		10		—			51,298
Total short-term investments	$	51,840	$	10	$	—		$	51,850
Total cash and cash equivalents and investments	$	98,357	$	10	$	—		$	98,367
	As of December 31, 2013
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
			(in thousands)
Cash and cash equivalents	$	37,499	$	—	$	—		$	37,499
Securities maturing within one year:
Certificates of deposit	552		—		—			552
U.S. treasury securities	91,075		3		(1		)	91,077
Total short-term investments	$	91,627	$	3	$	(1	)	$	91,629
Total cash and cash equivalents and investments	$	129,126	$	3	$	(1	)	$	129,128

There were no realized gains or losses for the three months ended March 31, 2014, and no realized gains or losses for the three months ended March 31, 2013. The cost of securities sold is based on the specific identification method.