Investment securities:

The amortized cost of securities and their fair values at December 31, 2018 and 2017 are shown below:



	December 31, 2018
	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair Value
Investment Securities
Available-for-sale debt securities
U.S. government agency securities	$	1,000	$	—	$	(11	)	$	989
Mortgage-backed securities - residential	520,654		1,191		(13,265		)	508,580
Municipals, tax exempt	138,994		1,565		(1,672		)	138,887
Treasury securities	7,385		—		(143		)	7,242
Total	$	668,033	$	2,756	$	(15,091	)	$	655,698

As of December 31, 2018, the Company also had $3,107 in marketable equity securities recorded at fair value. Net losses of $81 were recognized due to changes in fair value of these securities during the year ended December 31, 2018. As of January 1, 2018, the Company adopted ASU 2016-01 (See Note 1) and reclassified $3,604 of other securities without readily determinable market values to other assets.



	December 31, 2017
	Amortized cost		Gross unrealized gains		Gross unrealized losses			Fair Value
Investment Securities
Available-for-sale debt securities
U.S. government agency securities	$	999	$	—	$	(13	)	$	986
Mortgage-backed securities - residential	425,557		374		(7,150		)	418,781
Municipals, tax exempt	107,127		2,692		(568		)	109,251
Treasury securities	7,345		—		(93		)	7,252
Total debt securities	541,028		3,066		(7,824		)	536,270
Equity securities	7,870		1		(149		)	7,722
Total securities available-for-sale	$	548,898	$	3,067	$	(7,973	)	$	543,992

Securities pledged at December 31, 2018 and 2017 had carrying amounts of $326,215 and $337,604, respectively, and were pledged to secure a Federal Reserve Bank line of credit, public deposits and repurchase agreements.

There were no holdings of securities of any one issuer, other than the U.S. Government and its agencies, in an amount greater than 10% of shareholders' equity at December 31, 2018 and 2017.

Included in available-for-sale securities at December 31, 2018 and 2017 were $2,120 and $348, respectively, in trade date payables that were settled after year end.

The amortized cost and fair value of debt securities by contractual maturity at December 31, 2018 and 2017 are shown below. Maturities may differ from contractual maturities in mortgage-backed securities because the mortgage underlying the security may be called or repaid without any penalties. Therefore, mortgage-backed securities are not included in the maturity categories in the following maturity summary.



	Year Ended December 31,
	2018				2017
	Available-for-sale				Available-for-sale
	Amortized cost		Fair value		Amortized cost		Fair value
Due in one year or less	$	15,883	$	16,028	$	905	$	925
Due in one to five years	13,806		13,740		28,332		28,878
Due in five to ten years	18,539		18,387		19,218		19,588
Due in over ten years	99,151		98,963		67,016		68,098
	147,379		147,118		115,471		117,489
Mortgage-backed securities - residential	520,654		508,580		425,557		418,781
Total debt securities	$	668,033	$	655,698	$	541,028	$	536,270

Sales of available-for-sale securities were as follows:



	Year Ended December 31,
	2018		2017		2016
Proceeds from sales	$	2,742	$	94,743	$	271,148
Gross realized gains	8		1,277		4,755
Gross realized losses	44		48		348

The Company also recognized $1 and $1 on gains related to the early call of available for sale securities during the years ended December 31, 2018 and December 31, 2017, respectively.

The following tables show gross unrealized losses at December 31, 2018 and 2017, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position:



	December 31, 2018
	Less than 12 months					12 months or more					Total
	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss			Fair Value		Unrealized loss
U.S. government agency securities	$	—	$	—		$	989	$	(11	)	$	989	$	(11	)
Mortgage-backed securities - residential	60,347		(478		)	335,769		(12,787		)	396,116		(13,265		)
Municipals, tax exempt	27,511		(366		)	25,343		(1,306		)	52,854		(1,672		)
Treasury securities	—		—			7,242		(143		)	7,242		(143		)
Total debt securities	$	87,858	$	(844	)	$	369,343	$	(14,247	)	$	457,201	$	(15,091	)



	December 31, 2017
	Less than 12 months					12 months or more					Total
	Fair Value		Unrealized Loss			Fair Value		Unrealized Loss			Fair Value		Unrealized loss
U.S. government agency securities	$	—	$	—		$	986	$	(13	)	$	986	$	(13	)
Mortgage-backed securities - residential	107,611		(980		)	290,258		(6,170		)	397,869		(7,150		)
Municipals, tax exempt	7,354		(101		)	20,112		(467		)	27,466		(568		)
Treasury securities	7,252		(93		)	—		—			7,252		(93		)
Total debt securities	122,217		(1,174		)	311,356		(6,650		)	433,573		(7,824		)
Equity securities	—		—			3,050		(149		)	3,050		(149		)
	$	122,217	$	(1,174	)	$	314,406	$	(6,799	)	$	436,623	$	(7,973	)

As of December 31, 2018 and 2017, the Company’s securities portfolio consisted of 360 and 294 securities, 174 and 124 of which were in an unrealized loss position, respectively.

The Company evaluates available-for-sale debt securities with unrealized losses for other-than-temporary impairment (OTTI) on a quarterly basis and recorded no OTTI for the year ended December 31, 2018. During the year ended December 31, 2017, the Company recognized impairment of $945 on one of the equity securities without readily determinable market value. On January 1, 2018, this investment was reclassified to other assets. The Company considers an investment security impaired if the fair value of the security is less than its cost or amortized cost basis. For debt securities, the unrealized losses associated with these investment securities are primarily driven by interest rates and are not due to the credit quality of the securities. The Company currently does not intend to sell those investments with unrealized losses, and it is unlikely that the Company will be required to sell the investments before recovery of their amortized cost bases, which may be maturity.