INVESTMENTS

9 Months Ended

Sep. 30, 2021

Investments, Debt and Equity Securities [Abstract]

INVESTMENTS

INVESTMENTS

Investments available-for-sale

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

	September 30, 2021								December 31, 2020
(In thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Estimated Fair Value
U.S. treasuries and government agencies	$	47,477	$	260	$	(8)	$	47,729	$	42,750	$	549	$	(2)	$	43,297
State and municipal	325,384		5,486		(3,077)		327,793		377,108		13,470		(211)		390,367
Mortgage-backed and asset-backed	1,039,159		12,712		(5,247)		1,046,624		881,201		24,078		(847)		904,432
Corporate debt	7,000		409		—		7,409		9,100		825		—		9,925
Total investments available-for-sale	$	1,419,020	$	18,867	$	(8,332)	$	1,429,555	$	1,310,159	$	38,922	$	(1,060)	$	1,348,021

Any unrealized losses in the U.S. treasuries and government agencies, state and municipal, mortgage-backed and asset-backed investment securities at September 30, 2021 are due to changes in interest rates and not credit-related events. As such, no allowance for credit losses is required at September 30, 2021. Unrealized losses on investment 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.

The mortgage-backed securities portfolio at September 30, 2021 is composed entirely of either the most senior tranches of GNMA, FNMA or FHLMC collateralized mortgage obligations ($312.1 million), GNMA, FNMA or FHLMC mortgage-backed securities ($677.4 million) or SBA asset-backed securities ($57.1 million).

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

	September 30, 2021
	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	2	$	10,967	$	8	$	—	$	—	$	10,967	$	8
State and municipal	36	90,013		2,169		14,643		908		104,656		3,077
Mortgage-backed and asset-backed	60	446,119		4,789		15,604		458		461,723		5,247
Total	98	$	547,099	$	6,966	$	30,247	$	1,366	$	577,346	$	8,332

	December 31, 2020
	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	2	$	25,369	$	2	$	—	$	—	$	25,369	$	2
State and municipal	8	22,753		211		—		—		22,753		211
Mortgage-backed and asset-backed	24	44,746		154		76,879		693		121,625		847
Total	34	$	92,868	$	367	$	76,879	$	693	$	169,747	$	1,060

The estimated fair values and amortized costs of debt securities available-for-sale by contractual maturity at the dates indicated are provided in the following table. 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.

	September 30, 2021				December 31, 2020
(In thousands)	Fair Value		Amortized Cost		Fair Value		Amortized Cost
U.S. treasuries and government agencies:
One year or less	$	39,647	$	39,559	$	33,963	$	33,833
One to five years	8,082		7,918		9,334		8,917
Five to ten years	—		—		—		—
After ten years	—		—		—		—
State and municipal:
One year or less	14,173		14,009		16,581		16,458
One to five years	25,081		24,229		44,910		43,857
Five to ten years	43,958		43,207		59,059		56,130
After ten years	244,581		243,939		269,817		260,663
Mortgage-backed and asset-backed:
One year or less	7,975		7,916		1		1
One to five years	15,344		15,063		21,637		21,229
Five to ten years	319,947		319,621		74,142		72,481
After ten years	703,358		696,559		808,652		787,490
Corporate debt:
One year or less	—		—		—		—
One to five years	—		—		2,318		2,100
Five to ten years	7,409		7,000		7,607		7,000
After ten years	—		—		—		—
Total available-for-sale debt securities	$	1,429,555	$	1,419,020	$	1,348,021	$	1,310,159

At September 30, 2021 and December 31, 2020, investments available-for-sale with a book value of $532.4 million and $465.7 million, respectively, were pledged as collateral for certain government deposits and for 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 September 30, 2021 and December 31, 2020.

Equity securities

Other equity securities at the dates indicated are presented in the following table:

(In thousands)	September 30, 2021		December 31, 2020
Federal Reserve Bank stock	$	34,028	$	38,650
Federal Home Loan Bank of Atlanta stock	6,392		26,433
Marketable equity securities	677		677
Total equity securities	$	41,097	$	65,760