Marketable Securities

12 Months Ended

Dec. 31, 2016

Investments Debt And Equity Securities [Abstract]

Marketable Securities

4. Marketable Securities

The following table summarizes the available-for-sale securities held at December 31, 2016 and 2015 (in thousands):

	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
December 31, 2016
Description:
U.S. government agency securities and treasuries	$	79,411	$	—	$	(9	)	$	79,402
Total	$	79,411	$	—	$	(9	)	$	79,402

	Amortized Cost		Unrealized Gains		Unrealized Losses			Fair Value
December 31, 2015
Description:
U.S. government agency securities and treasuries	$	114,724	$	—	$	(178	)	$	114,546
Total	$	114,724	$	—	$	(178	)	$	114,546

The estimated market value of marketable securities by maturity date is as follows (in thousands):

	December 31,2016		December 31,2015
Due in one year or less	$	79,402	$	89,607
Due after one year through two years		—		24,939
Total	$	79,402	$	114,546

The amortized cost of available-for-sale securities is adjusted for amortization of premiums and accretion of discounts to maturity. There were no realized gains or losses recognized during the years ended December 31, 2016 and 2015, and as a result, the Company did not reclassify any amount out of accumulated other comprehensive loss for the same period.

The aggregate fair value of securities held by the Company in an unrealized loss position for less than twelve months as of December 31, 2016 was $62,897,000, which consisted of 2 U.S. government agency securities and 12 U.S. treasury securities. The aggregate fair value of securities held by the Company in an unrealized loss position for less than twelve months as of December 31, 2015 was $114,546,000, which consisted of 14 U.S. government agency securities and 10 U.S. treasury securities. To determine whether an other-than-temporary impairment exists, the Company performs an analysis to assess whether it intends to sell, or whether it would more likely than not be required to sell, the security before the expected recovery of the amortized cost basis. Where the Company intends to sell a security, or may be required to do so, the security’s decline in fair value is deemed to be other-than-temporary and the full amount of the unrealized loss is recognized in the consolidated statement of operations and comprehensive loss as an other-than-temporary impairment charge. When this is not the case, the Company performs additional analysis on all securities with unrealized losses to evaluate losses associated with the creditworthiness of the security. Credit losses are identified where the Company does not expect to receive cash flows, based on using a best estimate, sufficient to recover the amortized cost basis of a security and amount of the loss recognized in other income (expense). The Company has the intent and ability to hold all securities until recovery.

The Company does not intend to sell and it is unlikely that the Company will be required to sell the above investments before recovery of their amortized cost bases, which may be maturity. The Company determined there was no material change in the credit risk of the above investments, and as a result, the Company determined it did not hold any investments with an other-than-temporary impairment as of December 31, 2016 and 2015.