Investment Securities

12 Months Ended

Dec. 31, 2019

Investments, Debt and Equity Securities [Abstract]

INVESTMENT SECURITIES

The amortized cost, gross unrealized gains, gross unrealized losses and approximate market value of the Corporation's investment securities at the dates indicated were:



	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Available for sale at December 31, 2019
U.S. Government-sponsored agency securities	$	38,529	$	346	$	—	$	38,875
State and municipal	859,511		41,092		807		899,796
U.S. Government-sponsored mortgage-backed securities	842,349		10,378		1,404		851,323
Corporate obligations	31		—		—		31
Total available for sale	1,740,420		51,816		2,211		1,790,025
Held to maturity at December 31, 2019
U.S. Government-sponsored agency securities	15,619		1		37		15,583
State and municipal	354,115		15,151		107		369,159
U.S. Government-sponsored mortgage-backed securities	434,804		6,921		401		441,324
Foreign investment	1,500		—		—		1,500
Total held to maturity	806,038		22,073		545		827,566
Total Investment Securities	$	2,546,458	$	73,889	$	2,756	$	2,617,591

Available for sale at December 31, 2018
U.S. Government-sponsored agency securities	$	13,493	$	92	$	3	$	13,582
State and municipal	605,994		5,995		5,854		606,135
U.S. Government-sponsored mortgage-backed securities	530,209		634		8,396		522,447
Corporate obligations	31		—		—		31
Total available for sale	1,149,727		6,721		14,253		1,142,195
Held to maturity at December 31, 2018
U.S. Government-sponsored agency securities	22,618		—		545		22,073
State and municipal	197,909		2,858		872		199,895
U.S. Government-sponsored mortgage-backed securities	268,860		713		3,323		266,250
Foreign investment	1,000		—		1		999
Total held to maturity	490,387		3,571		4,741		489,217
Total Investment Securities	$	1,640,114	$	10,292	$	18,994	$	1,631,412

The change in unrealized gains/losses from December 31, 2018 to December 31, 2019 is primarily due to the changes in interest rates. The

longer term points on the yield curve have declined since year-end which increases the fair value of securities held in the portfolio.

The following table shows the Corporation’s gross unrealized losses and fair value, aggregated by investment category and length of time the individual securities have been in a continuous unrealized loss position at December 31, 2019 and 2018:



	Less than 12 Months				12 Months or Longer				Total
	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
Temporarily Impaired Available for Sale Securities at December 31, 2019
State and municipal	$	76,273	$	807	$	—	$	—	$	76,273	$	807
U.S. Government-sponsored mortgage-backed securities	127,673		1,326		20,796		78		148,469		1,404
Total Temporarily Impaired Available for Sale Securities	203,946		2,133		20,796		78		224,742		2,211
Temporarily Impaired Held to Maturity Securities at December 31, 2019
U.S. Government-sponsored agency securities	3,016		4		12,467		33		15,483		37
State and municipal	22,947		107		—		—		22,947		107
U.S. Government-sponsored mortgage-backed securities	124,253		364		7,991		37		132,244		401
Total Temporarily Impaired Held to Maturity Securities	150,216		475		20,458		70		$	170,674	545
Total Temporarily Impaired Investment Securities	$	354,162	$	2,608	$	41,254	$	148	$	395,416	$	2,756


	Less than 12 Months				12 Months or Longer				Total
	Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses		Fair Value		Gross Unrealized Losses
Temporarily Impaired Available for Sale Securities at December 31, 2018
U.S. Government-sponsored agency securities	$	1,490	$	3	$	—	$	—	$	1,490	$	3
State and municipal	234,431		3,958		38,028		1,896		272,459		5,854
U.S. Government-sponsored mortgage-backed securities	196,601		2,400		217,121		5,996		413,722		8,396
Total Temporarily Impaired Available for Sale Securities	432,522		6,361		255,149		7,892		687,671		14,253
Temporarily Impaired Held to Maturity Securities at December 31, 2018
U.S. Government-sponsored agency securities	—		—		22,073		545		22,073		545
State and municipal	14,952		369		16,786		503		31,738		872
U.S. Government-sponsored mortgage-backed securities	102,828		876		87,268		2,447		190,096		3,323
Foreign investment	—		—		999		1		999		1
Total Temporarily Impaired Held to Maturity Securities	117,780		1,245		127,126		3,496		244,906		4,741
Total Temporarily Impaired Investment Securities	$	550,302	$	7,606	$	382,275	$	11,388	$	932,577	$	18,994

Certain investments in debt securities are reported in the financial statements at amounts less than their historical cost. The historical cost of these investments totaled $398,172,000 and $951,571,000 at December 31, 2019 and 2018, respectively. Total fair value of these investments was $395,416,000 and $932,577,000, which was approximately 15.2 and 57.1 percent of the Corporation's available for sale and held to maturity investment portfolio at December 31, 2019 and 2018, respectively.

The Corporation's management believes the decline in fair value for these securities was temporary. Should the impairment of any of these securities become other-than-temporary, the cost basis of the investment will be reduced and the resulting loss recognized in net income during the period the OTTI is identified. The Corporation’s management has evaluated all securities with unrealized losses for OTTI and concluded no OTTI existed at December 31, 2019.

In determining the fair value of the investment securities portfolio, the Corporation utilizes a third party for portfolio accounting services, including market value input, for those securities classified as Level I and Level II in the fair value hierarchy. The Corporation has obtained an understanding of what inputs are being used by the vendor in pricing the portfolio and how the vendor classified these securities based upon these inputs. From these discussions, the Corporation’s management is comfortable that the classifications are proper. The Corporation has gained trust in the data for two reasons: (a) independent spot testing of the data is conducted by the Corporation through obtaining market quotes from various brokers on a periodic basis; and (b) actual gains or loss resulting from the sale of certain securities has proven the data to be accurate over time. Fair value of securities classified as Level 3 in the valuation hierarchy was determined using a discounted cash flow model that incorporated market estimates of interest rates and volatility in markets that have not been active.

U.S. Government-Sponsored Mortgage-Backed Securities

The unrealized losses on the Corporation's investment in mortgage-backed securities were a result of interest rate changes. The Corporation expects to recover the amortized cost basis over the term of the securities. Because the decline in market value is attributable to changes in interest rates and not credit quality, and because the Corporation does not intend to sell the investments and it is not more likely than not that the Corporation will be required to sell the investments before recovery of their amortized cost basis, which may be maturity, the Corporation does not consider those investments to be other-than-temporarily impaired at December 31, 2019. As noted in the table above, the mortgage-backed securities portfolio contains unrealized losses of $1,404,000 on twenty-seven securities and $401,000 on fifteen securities in the available for sale and held to maturity portfolios, respectively. All these securities are issued by a government-sponsored entity.

State and Municipal Securities and U.S. Government-Sponsored Agency Securities

The unrealized losses on the Corporation's investments in securities of state and political subdivisions and U.S. Government-Sponsored Agency securities were caused by interest rate increases. The contractual terms of those investments do not permit the issuer to settle the securities at a price less than the amortized cost basis of the investments. Because the Corporation does not intend to sell the investments and it is not more likely than not that the Corporation will be required to sell the investments before recovery of their amortized cost basis, which may be maturity, the Corporation does not consider those investments to be other-than-temporarily impaired at December 31, 2019. As noted in the table above, the state and municipal securities portfolio contains unrealized losses of $807,000 on thirty-eight securities and $107,000 on eighteen securities in the available for sale and held to maturity portfolios, respectively. The U.S. Government-Sponsored Agency securities portfolio contains no unrealized loses in the available for sale portfolio, and $37,000 on three securities in the held to maturity portfolio.

The amortized cost and fair value of securities available for sale and held to maturity at December 31, 2019 by contractual maturity are shown below. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties.



	Available for Sale				Held to Maturity
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
Maturity Distribution at December 31, 2019
Due in one year or less	$	1,134	$	1,136	$	9,920	$	10,105
Due after one through five years	5,031		5,141		45,197		45,654
Due after five through ten years	74,745		76,920		84,153		88,844
Due after ten years	817,161		855,505		231,964		241,639
	898,071		938,702		371,234		386,242
U.S. Government-sponsored mortgage-backed securities	842,349		851,323		434,804		441,324
Total Investment Securities	$	1,740,420	$	1,790,025	$	806,038	$	827,566

Securities with a carrying value of approximately $503,427,000, $416,155,000 and $475,999,000 were pledged at December 31, 2019, 2018 and 2017, respectively, to secure certain deposits and securities sold under repurchase agreements, and for other purposes as permitted or required by law.

The book value of securities sold under agreements to repurchase amounted to $182,856,000 at December 31, 2019, and $116,691,000 at

December 31, 2018.

Gross gains and losses on the sales and redemptions of available for sale securities for the for the years indicated are shown below.



	2019		2018		2017
Sales and Redemptions of Available for Sale Securities:
Gross gains	$	4,415	$	4,269	$	2,681
Gross losses	—		—		50