INVESTMENTS

3 Months Ended

Mar. 31, 2024

Investments, Debt and Equity Securities [Abstract]

Investments available-for-sale and held-to-maturity

The amortized cost and estimated fair values of investments available-for-sale and held-to-maturity at the dates indicated are presented in the following table:


	March 31, 2024								December 31, 2023
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
Available-for-sale debt securities:
U.S. treasuries and government agencies	$	96,866	$	—	$	(4,630)	$	92,236	$	101,678	$	—	$	(4,751)	$	96,927
State and municipal	310,502		—		(46,516)		263,986		311,505		1		(43,292)		268,214
Mortgage-backed and asset-backed	819,214		83		(74,778)		744,519		807,636		181		(70,277)		737,540




Total available-for-sale debt securities	$	1,226,582	$	83	$	(125,924)	$	1,100,741	$	1,220,819	$	182	$	(118,320)	$	1,102,681
Held-to-maturity debt securities:


Mortgage-backed and asset-backed	231,354		—		(38,556)		192,798		236,165		—		(35,754)		200,411
Total held-to-maturity debt securities	$	231,354	$	—	$	(38,556)	$	192,798	$	236,165	$	—	$	(35,754)	$	200,411
Total debt securities	$	1,457,936	$	83	$	(164,480)	$	1,293,539	$	1,456,984	$	182	$	(154,074)	$	1,303,092

Any unrealized losses in the U.S. treasuries and government agencies, state and municipal, mortgage-backed and asset-backed available-for-sale debt securities at March 31, 2024 are due to changes in interest rates and not credit-related events. As such, no allowance for credit losses is required at March 31, 2024. Unrealized losses on available-for-sale debt securities are expected to recover over time as these securities approach maturity. The Company does not intend to sell, nor is it more likely than not it will be required to sell, these securities and has sufficient liquidity to hold these securities for an adequate period of time, which may be maturity, to allow for any anticipated recovery in fair value.

All held-to-maturity investments are either issued by a direct governmental entity or a government-sponsored entity and have no historical evidence supporting expected credit losses. Therefore, the Company has estimated these losses at zero and will monitor this assumption in the future for any economic or governmental policies that could affect this assumption.

The available-for-sale and held-to-maturity mortgage-backed securities portfolio at March 31, 2024 is composed entirely of either the most senior tranches of GNMA, FNMA or FHLMC collateralized mortgage obligations ($451.9 million), GNMA, FNMA or FHLMC mortgage-backed securities ($557.9 million) or SBA asset-backed securities ($40.8 million).

Gross unrealized losses and fair value by length of time that the individual available-for-sale debt securities have been in an unrealized loss position at the dates indicated are presented in the following table:


	March 31, 2024
	Number of Securities	Less Than 12 Months				12 Months or More				Total
(Dollars in thousands)		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
U.S. treasuries and government agencies	9	$	—	$	—	$	92,236	$	4,630	$	92,236	$	4,630
State and municipal	123	3,789		48		258,977		46,468		262,766		46,516
Mortgage-backed and asset-backed	332	55,845		436		664,980		74,342		720,825		74,778

Total	464	$	59,634	$	484	$	1,016,193	$	125,440	$	1,075,827	$	125,924


	December 31, 2023
	Number of Securities	Less Than 12 Months				12 Months or More				Total
(Dollars in thousands)		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
U.S. treasuries and government agencies	10	$	—	$	—	$	96,927	$	4,751	$	96,927	$	4,751
State and municipal	123	4,162		84		262,081		43,208		266,243		43,292
Mortgage-backed and asset-backed	321	22,731		106		691,281		70,171		714,012		70,277

Total	454	$	26,893	$	190	$	1,050,289	$	118,130	$	1,077,182	$	118,320

The Company has allocated mortgage-backed securities into the four maturity groupings reflected in the following tables using the expected average life of the individual securities based on statistics provided by independent third-party industry sources.

Expected maturities will differ from contractual maturities as borrowers may have the right to prepay obligations with or without prepayment penalties.

The estimated fair values and amortized costs of available-for-sale and held-to-maturity debt securities by contractual maturity are provided in the following tables:


	March 31, 2024				December 31, 2023
(In thousands)	Fair Value		Amortized Cost		Fair Value		Amortized Cost
Available-for-sale debt securities
U.S. treasuries and government agencies:
One year or less	$	12,922	$	12,988	$	17,798	$	17,979
One to five years	79,314		83,878		79,129		83,699
Five to ten years	—		—		—		—
After ten years	—		—		—		—
State and municipal:
One year or less	28,318		28,739		22,345		22,793
One to five years	28,586		29,770		33,282		34,288
Five to ten years	48,992		57,965		46,355		54,487
After ten years	158,090		194,028		166,232		199,937
Mortgage-backed and asset-backed:
One year or less	26,396		26,704		20,814		21,111
One to five years	27,290		28,067		29,823		30,666
Five to ten years	267,178		292,078		256,924		280,209
After ten years	423,655		472,365		429,979		475,650










Total available-for-sale debt securities	$	1,100,741	$	1,226,582	$	1,102,681	$	1,220,819


	March 31, 2024				December 31, 2023
(In thousands)	Fair Value		Amortized Cost		Fair Value		Amortized Cost
Held-to-maturity debt securities










Mortgage-backed and asset-backed:
One year or less	$	—	$	—	$	—	$	—
One to five years	—		—		—		—
Five to ten years	30,070		33,326		31,434		34,458
After ten years	162,728		198,028		168,977		201,707
Total held-to-maturity debt securities	$	192,798	$	231,354	$	200,411	$	236,165

At March 31, 2024 and December 31, 2023, available-for-sale and held-to-maturity debt securities with a book value of $489.0 million and $729.0 million, respectively, were pledged and designated as collateral for certain government deposits, public and trust funds, securities sold under repurchase agreements and other purposes as required or permitted by law. The outstanding balance of no single issuer, except for U.S. Agencies securities, exceeded ten percent of stockholders' equity at March 31, 2024 and December 31, 2023.

Other investments

Other investments are presented in the following table:


(In thousands)	March 31, 2024		December 31, 2023
Federal Reserve Bank stock, at cost	$	39,152	$	39,125
Federal Home Loan Bank of Atlanta stock, at cost	33,566		35,805
Other	677		677
Total other investments, at cost	$	73,395	$	75,607