INVESTMENT SECURITIES

The following tables detail the amortized cost and the estimated fair value of our investments in available-for-sale and held-to-maturity debt securities as well as our equity investments. None of our investments in debt securities are classified as trading.



	March 31, 2018
(Dollars in thousands)	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss		Fair Value
Available-for-Sale Debt Securities⁽¹⁾
CMO	$	277,079	$	5	$	7,848	$	269,236
FNMA MBS	523,676		71		14,747		509,000
FHLMC MBS	99,860		3		2,564		97,299
GNMA MBS	33,063		149		929		32,283
	$	933,678	$	228	$	26,088	$	907,818
Held-to-Maturity Debt Securities
State and political subdivisions	$	159,672	$	310	$	818	$	159,164

Equity Investments ⁽²⁾
Visa Class B shares	$	14,100	$	15,346	$	—	$	29,446
Other equity investments	3,947		—		30		3,917
	$	18,047	$	15,346	$	30	$	33,363


⁽¹⁾	Held-to–maturity securities transferred from available-for-sale are included in held-to-maturity at fair value at the time of transfer. The amortized cost of held-to-maturity securities included net unrealized gains of $1.5 million at March 31, 2018 related to securities transferred, which are offset in Accumulated other comprehensive loss, net of tax.


⁽²⁾	Equity investments are included in Other investments in the unaudited Consolidated Statements of Financial Condition.



	December 31, 2017
(Dollars in thousands)	Amortized Cost		Gross Unrealized Gain		Gross Unrealized Loss		Fair Value
Available-for-Sale Debt Securities⁽¹⁾
CMO	$	250,592	$	88	$	4,141	$	246,539
FNMA MBS	479,218		941		6,172		473,987
FHLMC MBS	88,681		118		924		87,875
GNMA MBS	29,300		209		411		29,098
	$	847,791	$	1,356	$	11,648	$	837,499
Held-to-Maturity Debt Securities
State and political subdivisions	$	161,186	$	1,758	$	91	$	162,853

Equity Investments⁽²⁾
Visa Class B shares	$	14,048	$	—	$	—	$	14,048
Other equity investments	3,943		—		20		3,923
	$	17,991	$	—	$	20	$	17,971


⁽¹⁾	Held-to–maturity securities transferred from available-for-sale are included in held-to-maturity at fair value at the time of transfer. The amortized cost of held-to-maturity securities included net unrealized gains of $1.6 million at December 31, 2017 related to securities transferred, which are offset in Accumulated other comprehensive loss, net of tax.


⁽²⁾	Equity investments are included in Other investments in the unaudited Consolidated Statements of Financial Condition.

The scheduled maturities of our available-for-sale debt securities at March 31, 2018 and December 31, 2017 are presented in the table below:



	Available for Sale
	Amortized		Fair
(Dollars in thousands)	Cost		Value
March 31, 2018
Within one year	$	—	$	—
After one year but within five years	19,963		19,389
After five years but within ten years	180,927		173,171
After ten years	732,788		715,258
	$	933,678	$	907,818
December 31, 2017
Within one year	$	—	$	—
After one year but within five years	20,051		19,825
After five years but within ten years	179,812		175,583
After ten years	647,928		642,091
	$	847,791	$	837,499

The scheduled maturities of our held-to-maturity debt securities at March 31, 2018 and December 31, 2017 are presented in the table below:



	Held to Maturity
	Amortized		Fair
(Dollars in thousands)	Cost		Value
March 31, 2018
Within one year	$	160	$	160
After one year but within five years	6,867		6,850
After five years but within ten years	20,042		19,930
After ten years	132,603		132,224
	$	159,672	$	159,164
December 31, 2017
Within one year	$	322	$	320
After one year but within five years	5,895		5,894
After five years but within ten years	18,751		18,873
After ten years	136,218		137,766
	$	161,186	$	162,853

Mortgage-backed securities (MBS) may have expected maturities that differ from their contractual maturities. These differences arise because issuers may have the right to call securities and borrowers may have the right to prepay obligations with or without prepayment penalty.

Investment securities with fair market values aggregating $619.0 million and $688.2 million were pledged as collateral for retail customer repurchase agreements, municipal deposits, and other obligations as of March 31, 2018 and December 31, 2017, respectively.

During the three months ended March 31, 2018, we sold $7.0 million of debt securities categorized as available for sale, resulting in realized gains of less than $0.1 million and no realized losses. During the three months ended March 31, 2017, we sold $263.0 million of debt securities categorized as available for sale, resulting in realized gains of $0.3 million and one security with an immaterial realized loss. The cost basis of all debt securities sales is based on the specific identification method.

As of March 31, 2018 and December 31, 2017, our debt securities portfolio had remaining unamortized premiums of $13.9 million and $14.1 million, respectively, and unaccreted discounts of $1.3 million as of both March 31, 2018 and December 31, 2017.

For debt securities with unrealized losses, the table below shows our gross unrealized losses and fair value by investment category and length of time that individual debt securities were in a continuous unrealized loss position at March 31, 2018.



	Duration of Unrealized Loss Position
	Less than 12 months				12 months or longer				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(Dollars in thousands)	Value		Loss		Value		Loss		Value		Loss
Available-for-sale debt securities:
CMO	$	186,243	$	4,292	$	77,903	$	3,556	$	264,146	$	7,848
FNMA MBS	339,535		7,581		122,243		7,166		461,778		14,747
FHLMC MBS	76,822		1,463		20,401		1,101		97,223		2,564
GNMA MBS	10,537		265		14,127		664		24,664		929
Total temporarily impaired investments	$	613,137	$	13,601	$	234,674	$	12,487	$	847,811	$	26,088

Held-to-maturity debt securities:
State and political subdivisions	$	92,114	$	708	$	5,372	$	110	$	97,486	$	818
Total temporarily impaired investments	$	92,114	$	708	$	5,372	$	110	$	97,486	$	818

Other investments	$	—	$	—	$	617	$	30	$	617	$	30

For investment securities with unrealized losses, the table below shows our gross unrealized losses and fair value by investment category and length of time that individual securities were in a continuous unrealized loss position at December 31, 2017.



	Duration of Unrealized Loss Position
	Less than 12 months				12 months or longer				Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(Dollars in thousands)	Value		Loss		Value		Loss		Value		Loss
Available-for-sale debt securities:
CMO	$	146,726	$	1,820	$	77,149	$	2,321	$	223,875	$	4,141
FNMA MBS	204,921		1,479		126,342		4,693		331,263		6,172
FHLMC MBS	42,514		269		21,405		655		63,919		924
GNMA MBS	4,615		56		14,782		355		19,397		411
Total temporarily impaired investments	$	398,776	$	3,624	$	239,678	$	8,024	$	638,454	$	11,648

Held-to-maturity debt securities:
State and political subdivisions	$	23,404	$	59	$	5,625	$	32	$	29,029	$	91
Total temporarily impaired investments	$	23,404	$	59	$	5,625	$	32	$	29,029	$	91

Other investments	$	—	$	—	$	624	$	20	$	624	$	20

At March 31, 2018, we owned debt securities totaling $945.3 million for which the amortized cost basis exceeded fair value. Total unrealized losses on these securities were $26.9 million at March 31, 2018. The temporary impairment is the result of changes in market interest rates subsequent to purchase. Our investment portfolio is reviewed each quarter for indications of OTTI. This review includes analyzing the length of time and the extent to which the fair value has been lower than the amortized cost, the financial condition and near-term prospects of the issuer, including any specific events which may influence the operations of the issuer and our intent and ability to hold the investment for a period of time sufficient to allow for full recovery of the unrealized loss. We evaluate our intent and ability to hold debt securities based upon our investment strategy for the particular type of security and our cash flow needs, liquidity position, capital adequacy and interest rate risk position. We do not have the intent to sell, nor is it more likely-than-not we will be required to sell these securities before we are able to recover the amortized cost basis.

All debt securities, with the exception of one having a fair value of $0.8 million at March 31, 2018, were AA-rated or better at the time of purchase and remained investment grade at March 31, 2018. All securities were evaluated for OTTI at March 31, 2018 and December 31, 2017. The result of this evaluation showed no OTTI as of March 31, 2018 or December 31, 2017. The estimated weighted average duration of MBS was 5.42 years at March 31, 2018.