Cash and Cash Equivalents and Investments

6 Months Ended

Jun. 30, 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 June 30, 2014 and December 31, 2013 are as follows:

	As of June 30, 2014
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	(in thousands)
Cash and cash equivalents	$	27,725	$	—	$	—		$	27,725
Securities maturing within one year:
Certificates of deposit	552		—		—			552
U.S. treasury securities	50,762		5		—			50,767
Total short-term investments	$	51,314	$	5	$	—		$	51,319
Total cash and cash equivalents and investments	$	79,039	$	5	$	—		$	79,044
	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 six months ended June 30, 2014, and no realized gains or losses for the six months ended June 30, 2013. The cost of securities sold is based on the specific identification method.