Note 5 — Investment Securities

The following is the amortized cost and fair value of investment securities held to maturity:


			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
(Dollars in thousands)	Cost		Gains		Losses		Value
March 31, 2018:
State and municipal obligations	$	1,274	$	10	$	—	$	1,284
December 31, 2017:
State and municipal obligations	$	2,529	$	27	$	—	$	2,556
March 31, 2017:
State and municipal obligations	$	6,095	$	122	$	—	$	6,217

The following is the amortized cost and fair value of investment securities available for sale:


			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
(Dollars in thousands)	Cost		Gains		Losses		Value
March 31, 2018:
Government-sponsored entities debt*	$	91,483	$	—	$	(1,737)	$	89,746
State and municipal obligations		224,994		2,232		(1,540)		225,686
Mortgage-backed securities**		1,353,356		248		(28,199)		1,325,405
Corporate securities		—		—		—		—
	$	1,669,833	$	2,480	$	(31,476)	$	1,640,837
December 31, 2017:
Government-sponsored entities debt*	$	86,535	$	51	$	(1,077)	$	85,509
State and municipal obligations		216,812		3,749		(124)		220,437
Mortgage-backed securities**		1,350,200		2,103		(11,616)		1,340,687
Corporate securities		1,560		—		—		1,560
	$	1,655,107	$	5,903	$	(12,817)	$	1,648,193
March 31, 2017:
Government-sponsored entities debt*	$	93,995	$	25	$	(721)	$	93,299
State and municipal obligations		196,241		4,183		(140)		200,284
Mortgage-backed securities**		1,084,764		5,095		(6,420)		1,083,439
Corporate stocks		2,433		624		(291)		2,766
	$	1,377,433	$	9,927	$	(7,572)	$	1,379,788

* - The Company’s government-sponsored entities holdings are comprised of debt securities offered by Federal Home Loan Mortgage Corporation (“FHLMC”) or Freddie Mac, Federal National Mortgage Association (“FNMA”) or Fannie Mae, FHLB, and Federal Farm Credit Banks (“FFCB”).

** - All of the mortgage-backed securities are issued by government-sponsored entities; there are no private-label holdings. Also, included in the Company’s mortgage-backed securities are debt securities offered by the Small Business Administration (“SBA”), which have the full faith and credit backing of the United States Government.

The following is the amortized cost and fair value of other investment securities:


			Gross		Gross
	Amortized		Unrealized		Unrealized		Fair
(Dollars in thousands)	Cost		Gains		Losses		Value
March 31, 2018:
Federal Home Loan Bank stock	$	17,399	$	—	$	—	$	17,399
Investment in unconsolidated subsidiaries		3,563		—		—		3,563
Other nonmarketable investment securities		2,517		—		—		2,517
	$	23,479	$	—	$	—	$	23,479
December 31, 2017:
Federal Home Loan Bank stock	$	16,967	$	—	$	—	$	16,967
Investment in unconsolidated subsidiaries		3,563		—		—		3,563
Other nonmarketable investment securities		2,517		—		—		2,517
	$	23,047	$	—	$	—	$	23,047
March 31, 2017:
Federal Home Loan Bank stock	$	11,239	$	—	$	—	$	11,239
Investment in unconsolidated subsidiaries		2,262		—		—		2,262
Other nonmarketable investment securities		1,225		—		—		1,225
	$	14,726	$	—	$	—	$	14,726

The amortized cost and fair value of debt securities at March 31, 2018 by contractual maturity are detailed below. Expected maturities may differ from contractual maturities because borrowers may have the right to call or prepay obligations with or without prepayment penalties.


	Securities				Securities
	Held to Maturity				Available for Sale
	Amortized		Fair		Amortized		Fair
(Dollars in thousands)	Cost		Value		Cost		Value
Due in one year or less	$	—	$	—	$	1,173	$	1,175
Due after one year through five years		—		—		122,525		121,675
Due after five years through ten years		1,274		1,284		374,833		369,402
Due after ten years		—		—		1,171,302		1,148,585
	$	1,274	$	1,284	$	1,669,833	$	1,640,837

Information pertaining to the Company’s securities with gross unrealized losses at March 31, 2018, December 31, 2017 and March 31, 2017, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position is as follows:


	Less Than				Twelve Months
	Twelve Months				or More
	Gross				Gross
	Unrealized		Fair		Unrealized		Fair
(Dollars in thousands)	Losses		Value		Losses		Value
March 31, 2018:
Securities Available for Sale
Government-sponsored entities debt	$	918	$	34,712	$	819	$	55,034
State and municipal obligations		1,523		69,118		17		724
Mortgage-backed securities		17,030		938,924		11,169		304,731
Corporate securities		—		—		—		—
	$	19,471	$	1,042,754	$	12,005	$	360,489
December 31, 2017:
Securities Available for Sale
Government-sponsored entities debt	$	403	$	27,442	$	674	$	52,324
State and municipal obligations		124		17,400		—		—
Mortgage-backed securities		4,493		610,051		7,123		322,258
Corporate securities		—		—		—		—
	$	5,020	$	654,893	$	7,797	$	374,582
March 31, 2017:
Securities Available for Sale
Government-sponsored entities debt	$	721	$	87,609	$	—	$	—
State and municipal obligations		140		10,984		—		—
Mortgage-backed securities		6,349		601,953		71		1,940
Corporate stocks		—		—		291		1,451
	$	7,210	$	700,546	$	362	$	3,391

Management evaluates securities for other-than-temporary impairment (“OTTI”) on at least a quarterly basis, and more frequently when economic or market concerns warrant such evaluation. Consideration is given to (1) the financial condition and near-term prospects of the issuer, (2) the outlook for receiving the contractual cash flows of the investments, (3) the length of time and the extent to which the fair value has been less than cost, (4) the intent and ability of the Company to retain its investment in the issuer for a period of time sufficient to allow for any anticipated recovery in fair value or for a debt security whether it is more-likely-than-not that the Company will be required to sell the debt security prior to recovering its fair value, and (5) the anticipated outlook for changes in the general level of interest rates. All debt securities available for sale in an unrealized loss position as of March 31, 2018 continue to perform as scheduled. As part of the Company’s evaluation of its intent and ability to hold investments for a period of time sufficient to allow for any anticipated recovery in the market, the Company considers its investment strategy, cash flow needs, liquidity position, capital adequacy and interest rate risk position. The Company does not currently intend to sell the securities within the portfolio and it is not more-likely-than-not that the Company will be required to sell the debt securities; therefore, management does not consider these investments to be other-than-temporarily impaired at March 31, 2018.

Management continues to monitor all of the Company’s securities with a high degree of scrutiny. There can be no assurance that the Company will not conclude in future periods that conditions existing at that time indicate some or all of its securities may be sold or are other than temporarily impaired, which would require a charge to earnings in such periods.