Marketable Securities

The Company has evaluated its investment policies and determined that all of its investment securities are to be classified as available-for-sale. Available-for-sale securities are carried at fair value, with the unrealized gains and losses reported in Stockholders’ equity under the caption “Accumulated other comprehensive loss.” Realized gains and losses on available-for-sale securities are included in “Other expense” in the Condensed Consolidated Statements of Operations. The Company records other-than-temporary impairment charges for its available-for-sale investments when it intends to sell the securities, it is more-likely-than not that it will be required to sell the securities before a recovery, or when it does not expect to recover the entire amortized cost basis of the securities. The cost of securities sold is based on the specific identification method.

The Company has determined that the gross unrealized losses on its marketable securities at June 30, 2017 and December 31, 2016 are temporary in nature. The Company reviews its investment portfolio to identify and evaluate investments that have indications of possible impairment. Factors considered in determining whether a loss is other-than-temporary include the length of time and extent to which fair value has been less than the cost basis, credit quality and the Company’s ability and intent to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value.

At June 30, 2017 and December 31, 2016, marketable securities are categorized as follows:



	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Fair Value
June 30, 2017
Municipal notes and bonds	$	90,389	$	21	$	(7	)	$	90,403
Corporate bonds	841		—		—			841
Total marketable securities	$	91,230	$	21	$	(7	)	$	91,244
December 31, 2016
Municipal notes and bonds	$	87,088	$	6	$	(65	)	$	87,029
Corporate bonds	842		1		—			843
Total marketable securities	$	87,930	$	7	$	(65	)	$	87,872

The amortized cost and estimated fair value of marketable securities classified by the maturity date listed on the security, regardless of the Condensed Consolidated Balance Sheet classification, is as follows at June 30, 2017 and December 31, 2016:



	June 30, 2017				December 31, 2016
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Due within one year	$	77,592	$	77,601	$	82,498	$	82,445
Due after one through five years	13,638		13,643		5,432		5,427
Due after five through ten years	—		—		—		—
Due after ten years	—		—		—		—
Total marketable securities	$	91,230	$	91,244	$	87,930	$	87,872

The following table summarizes the estimated fair value and gross unrealized holding losses of marketable securities, aggregated by investment instrument and period of time in an unrealized loss position at June 30, 2017 and December 31, 2016:



	Unrealized Loss Position For Less Than 12 Months					Unrealized Loss Position For Greater Than 12 Months
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
June 30, 2017
Municipal notes and bonds	$	26,062	$	(7	)	$	—	$	—
Corporate bonds	—		—			—		—
Total	$	26,062	$	(7	)	$	—	$	—
December 31, 2016
Municipal notes and bonds	$	64,918	$	(65	)	$	—	$	—
Corporate bonds	—		—			—		—
Total	$	64,918	$	(65	)	$	—	$	—

See Note 2 for additional discussion regarding the fair value of the Company’s marketable securities.