Marketable Investment Securities

9 Months Ended

Sep. 30, 2019

(3) Marketable Investment Securities

The Company has classified its marketable investment securities as available-for-sale securities, all of which are debt securities. These securities are carried at fair value with unrealized holding gains and losses, net of the related tax effect, included in accumulated other comprehensive income (loss) in stockholders’ equity until realized. Gains and losses on investment security transactions are reported on the specific-identification method. Dividend income is recognized on the ex-dividend date and interest income is recognized on an accrual basis. The amortized cost, gross unrealized holding gains, gross unrealized holding losses, and fair value for available-for-sale securities by major security type and class of security at September 30, 2019 and December 31, 2018 were as follows:


			Gross		Gross
			unrealized		unrealized
	Amortized		holding		holding		Aggregate
September 30, 2019	Cost		gains		losses		fair value
Government bonds and notes	$	849,887	$	36	$	—	$	849,923
Corporate bonds, notes and commercial paper		4,030,728		225		—		4,030,953
	$	4,880,615	$	261	$	—	$	4,880,876


			Gross		Gross
			unrealized		unrealized
	Amortized		holding		holding		Aggregate
December 31, 2018	Cost		gains		losses		fair value
Government bonds and notes	$	897,481	$	—	$	(100)	$	897,381
Corporate bonds, notes and commercial paper		6,276,519		—		(863)		6,275,656
	$	7,174,000	$	—	$	(963)	$	7,173,037

Maturities of debt securities classified as available-for-sale securities at September 30, 2019 are as follows:


	Amortized		Aggregate
September 30, 2019	Cost		fair value
Due within one year	$	4,880,615	$	4,880,876

There were no sales of marketable investment securities during the three and nine months ended September 30, 2019 and 2018 and therefore no realized gains or losses. Additionally, $8.5 million and $10.4 million of marketable investment securities matured during the three months ended September 30, 2019 and 2018, respectively. Also, $17.5 million and $27.0 million of marketable investment securities matured during the nine months ended September 30, 2019 and 2018, respectively. The Company determined there were no other-than-temporary impairments for the three and nine months ended September 30, 2019 and 2018.