Marketable Securities

6 Months Ended

Jun. 30, 2016

Investments Debt And Equity Securities [Abstract]

Marketable Securities

7. Marketable Securities

The Company classifies marketable securities with a remaining maturity when purchased of greater than three months as available-for-sale. Available-for-sale securities may consist of U.S. government agency securities, commercial paper, corporate notes and bonds and certificates of deposit, which are maintained by an investment manager. Available-for-sale securities are carried at fair value, with the unrealized gains and losses included in other comprehensive income (loss) as a component of stockholders’ deficit until realized. The amortized cost of securities in this category is adjusted for amortization of premiums and accretion of discounts to maturity. Realized gains and losses are recognized within interest income.

Cash equivalents and marketable securities as of June 30, 2016 consisted of the following:

	June 30, 2016
(in thousands)	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
Cash equivalents:
Money market funds	$	8,476	$	—	$	—		$	8,476
Corporate debt securities		2,504		—		(1	)		2,503
Total cash equivalents	$	10,980	$	—	$	(1	)	$	10,979
Marketable securities:
Commercial paper	$	20,980	$	4	$	(5	)	$	20,979
Corporate debt securities		21,200		1		(1	)		21,200
U.S. government agency securities		18,994		3		—			18,997
Total marketable securities	$	61,174	$	8	$	(6	)	$	61,176

As of December 31, 2015, the Company maintained only cash equivalents comprised of money market funds.

There were no realized gains or losses on available-for-sale securities during the three or six months ended June 30, 2016 or 2015. As of June 30, 2016, the Company held six individual cash equivalents or available-for-sale securities that had been in an unrealized loss position for less than twelve months, and the aggregate fair value of such securities was $22.6 million. As of June 30, 2016, the Company did not intend to sell, and it was not more likely than not that the Company would be required to sell, the securities in an unrealized loss position before recovery of their amortized cost bases. The Company determined that there was no material change in the credit risk of the investments. As a result, the Company determined it did not hold any securities with an other-than-temporary-impairment as of June 30, 2016.