Marketable Securities

Marketable securities consist primarily of certificates of deposit and corporate bonds with maturities greater than three months and up to four years at the time of purchase. These securities, which are classified as available-for-sale, are carried at fair value, with unrealized gains and losses, net of any tax effect, reported in stockholders’ equity as accumulated other comprehensive income (loss). These securities are classified as current and non-current marketable securities based upon their maturities. Amortization of premiums and discounts is included in interest income. For the three and nine months ended September 30, 2018 and 2017, the amortization of bond premiums totaled $175 and $557 compared to $219 and $771, respectively. The value of these securities may fluctuate as a result of changes in market interest rates and credit risk. The schedule of maturities at September 30, 2018 and December 31, 2017 is as follows:



	Maturities as of September 30, 2018				Maturities as of December 31, 2017
	1 Year or Less		1 to 4 Years		1 Year or Less		1 to 4 Years
Corporate bonds	$	26,451	$	—	$	11,979	$	29,523
Certificates of deposit	31,445		—		52,048		—
Total	$	57,896	$	—	$	64,027	$	29,523

For the three and nine months ended September 30, 2018, losses of $0 and $182 were reclassified from accumulated other comprehensive income and recognized in the income statement in interest and other income compared to gains of $24 and $52 for the comparable periods in 2017. For the nine months ended September 30, 2018, current marketable securities included unrealized losses of $113 and no non-current marketable securities were held by the Company. For the comparable period in 2017, current marketable securities included unrealized gains of $4 and unrealized losses of $93 while non-current marketable securities included unrealized gains of $37 and unrealized losses of $29.