INVESTMENT SECURITIES AVAILABLE FOR SALE

The components of investment securities available for sale at September 30, 2017 were as follows:



	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Marketable equity securities	$	35,160	$	12,990	$	(62	)	$	48,088
Mutual funds invested in fixed income securities	20,855		168		—			21,023
Marketable debt securities	85,172		362		—			85,534
Total investment securities available for sale	$	141,187	$	13,520	$	(62	)	$	154,645

The components of investment securities available for sale at December 31, 2016 were as follows:



	Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value
Marketable equity securities	$	34,956	$	16,141	$	(254	)	$	50,843
Mutual funds invested in fixed income securities	20,507		81		(6		)	20,582
Marketable debt securities	85,297		181		—			85,478
Total investment securities available for sale	$	140,760	$	16,403	$	(260	)	$	156,903

The table below summarizes the maturity dates of marketable debt securities at September 30, 2017.



Investment Type:	Market Value		Under 1 Year		1 Year up to 5 Years		More than 5 Years
U.S. Government securities	$	28,696	$	—	$	28,696	$	—
Corporate securities	40,372		9,079		31,293		—
U.S. mortgage-backed securities	5,089		—		22		5,067
Commercial mortgage-backed securities	433		—		—		433
Commercial paper	7,976		7,976		—		—
Index-linked U.S. bonds	2,314		—		2,314		—
Foreign fixed-income securities	654		—		654		—
Total marketable debt securities by maturity dates	$	85,534	$	17,055	$	62,979	$	5,500

The available-for-sale investment securities with continuous unrealized losses for less than 12 months and 12 months or greater and their related fair values were as follows:



	In loss position for
	Less than 12 months					12 months or more
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses		Total Fair Value		Total Unrealized Losses
September 30, 2017
Marketable equity securities	$	5,958	$	(62	)	$	—	$	—	$	5,958	$	(62	)
	$	5,958	$	(62	)	$	—	$	—	$	5,958	$	(62	)

December 31, 2016
Marketable equity securities	$	5,746	$	(254	)	$	—	$	—	$	5,746	$	(254	)
Mutual funds invested in fixed income securities	10,253		(6		)	—		—		10,253		(6		)
	$	15,999	$	(260	)	$	—	$	—	$	15,999	$	(260	)

Unrealized losses from mutual funds invested in fixed-income securities are primarily attributable to changes in interest rates. Unrealized losses from equity securities are due to market price movements. The Company believes the unrealized losses associated with the Company’s mutual funds and equity securities will be recovered in the future.

Gross realized gains and losses on available-for-sale investment securities were as follows:



	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2017			2016			2017			2016
Gross realized gains on sales	$	141		$	224		$	419		$	1,157
Gross realized losses on sales	(45		)	(82		)	(136		)	(309		)
Gains on sale of investment securities available for sale	$	96		$	142		$	283		$	848

Gross realized losses on other-than-temporary impairments	$	(53	)	$	(54	)	$	(179	)	$	(4,916	)

The Company recorded an “Other-than-temporary impairment” charge of $53 and $179 during the three and nine months ended September 30, 2017, respectively. The Company recorded an “Other-than-temporary impairment” charge of $54 and $4,916 during the three and nine months ended September 30, 2016, respectively.

Although management generally does not have the intent to sell any specific securities at the end of the period, in the ordinary course of managing the Company’s investment securities portfolio, management may sell securities prior to their maturities for a variety of reasons, including diversification, credit quality, yield and liquidity requirements.

Proceeds from investment securities sales totaled $23,066 and $81,235 and proceeds from early redemptions by issuers totaled $97,011 and $12,185 in the nine months ended September 30, 2017 and 2016, respectively, mainly from the sales and redemptions of Corporate securities and U.S. Government securities.