Marketable Securities

6 Months Ended

Jun. 30, 2016

Investments, Debt and Equity Securities [Abstract]

Marketable Securities

Marketable Securities

At June 30, 2016, marketable securities consisted of the following (in thousands):

	Amortized Cost		Unrealized Gains		Unrealized Losses			Aggregate Fair Value
U.S. treasury debt securities	$	3,507	$	6	$	—		$	3,513
U.S. corporate debt securities	7,513		19		(1		)	7,531
Money market funds	34,667		—		—			34,667
	$	45,687	$	25	$	(1	)	$	45,711
Included in cash and cash equivalents	$	34,667	$	—	$	—		$	34,667
Included in marketable securities	$	11,020	$	25	$	(1	)	$	11,044

At December 31, 2015, marketable securities consisted of the following (in thousands):

	Amortized Cost		Unrealized Gains		Unrealized Losses			Aggregate Fair Value
U.S. treasury debt securities	$	4,805	$	—	$	(31	)	$	4,774
U.S. corporate debt securities	12,679		1		(34		)	12,646
Money market funds	53,365		—		—			53,365
	$	70,849	$	1	$	(65	)	$	70,785
Included in cash and cash equivalents	$	53,365	$	—	$	—		$	53,365
Included in marketable securities	$	17,484	$	1	$	(65	)	$	17,420

The following table presents gross unrealized losses and fair values for those marketable securities that were in an unrealized loss position as of June 30, 2016, aggregated by investment category and the length of time that individual securities have been in a continuous loss position (in thousands):

	As of June 30, 2016
	Less than 12 months					12 months or greater
	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss
U.S. corporate debt securities	$	1,078	$	(1	)	$	—	$	—
Total	$	1,078	$	(1	)	$	—	$	—

We do not believe any of the unrealized losses represented an other-than-temporary impairment based on our evaluation of available evidence, which includes our intent as of June 30, 2016 to hold these investments until the cost basis is recovered.