Marketable Securities

9 Months Ended

Sep. 30, 2016

Investments Debt And Equity Securities [Abstract]

Marketable Securities

6. Marketable Securities

Our investment policy is consistent with the definition of available-for-sale securities.  We do not buy and hold securities principally for the purpose of selling them in the near future nor do we intend to hold securities to maturity.  Rather, our policy is focused on the preservation of capital, liquidity and return.  From time to time, we may sell certain securities but the objectives are generally not to generate profits on short-term differences in price.  

The following tables summarize, by major security type, our assets that are measured at fair value on a recurring basis (in thousands):

	September 30, 2016
	Amortized		Gross Unrealized		Gross Unrealized			Estimated Fair
	Cost		Gains		Losses			Value
Corporate debt securities	$	24,343	$	—	$	(9	)	$	24,334

	December 31, 2015
	Amortized		Gross Unrealized		Gross Unrealized		Estimated Fair
	Cost		Gains		Losses		Value
Corporate debt securities	$	325	$	—	$	—	$	325

The aggregate fair value of investments in an unrealized loss position was $17,138,000 as of September 30, 2016. Because we do not intend to sell the investments that are in an unrealized loss position and it is not likely that we will be required to sell any investments before recovery of their amortized cost basis, we do not consider these investments with an unrealized loss to be other-than-temporarily impaired as of September 30, 2016.

There were no marketable securities in an unrealized loss position as of December 31, 2015.

There were no gross realized gains or losses from the sale or maturity of marketable securities during the nine months ended September 30, 2016 or the year ended December 31, 2015.  

During the nine months ended September 30, 2016, we recognized gross interest income on securities of $173,000.  Interest income was offset by amortization expense on securities of $20,000 during the nine months ended September 30, 2016, and reported net within interest income on the consolidated statements of operations.

During the year ended December 31, 2015, we recognized gross interest income on securities of $30,000.  Interest income was offset by amortization expense on securities of $13,000 during 2015, and reported net within interest income on the consolidated statements of operations.

The estimated fair value of investments by contractual maturity is as follows (in thousands):

	September 30,		December 31,
	2016		2015
Due within one year	$	24,334	$	325
Due after one year and through 5 years		—		—
Due after 5 years and through 10 years		—		—
Due after 10 years		—		—
Total	$	24,334	$	325