INVESTMENTS (Tables)

12 Months Ended

Dec. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Amortized Cost and Estimated Fair Values of Investments

The amortized cost and estimated fair values of investments available-for-sale and held-to-maturity at December 31 are presented in the following table:

	2022								2021
(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	$	100,926	$	—	$	(7,304)	$	93,622	$	68,487	$	202	$	(150)	$	68,539
State and municipal	322,519		4		(56,526)		265,997		323,286		6,561		(3,445)		326,402
Mortgage-backed and asset-backed	943,398		73		(88,552)		854,919		1,074,577		8,203		(11,825)		1,070,955
Total available-for-sale debt securities	$	1,366,843	$	77	$	(152,382)	$	1,214,538	$	1,466,350	$	14,966	$	(15,420)	$	1,465,896
Held-to-maturity debt securities:
Mortgage-backed and asset-backed	259,452		—		(39,329)		220,123		—		—		—		—
Total held-to-maturity debt securities	$	259,452	$	—	$	(39,329)	$	220,123	$	—	$	—	$	—	$	—
Total debt securities	$	1,626,295	$	77	$	(191,711)	$	1,434,661	$	1,466,350	$	14,966	$	(15,420)	$	1,465,896

Gross Unrealized Losses and Fair Value by Length of Time

Gross unrealized losses and fair values by length of time that individual available-for-sale securities have been in an unrealized loss position at December 31 are presented in the following tables:

	December 31, 2022
	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	$	53,139	$	3,653	$	40,483	$	3,651	$	93,622	$	7,304
State and municipal	130	200,439		30,803		62,482		25,723		262,921		56,526
Mortgage-backed and asset-backed	324	526,387		44,952		297,216		43,600		823,603		88,552
Total	464	$	779,965	$	79,408	$	400,181	$	72,974	$	1,180,146	$	152,382

	December 31, 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	5	$	49,695	$	150	$	—	$	—	$	49,695	$	150
State and municipal	32	63,206		2,288		21,740		1,157		84,946		3,445
Mortgage-backed and asset-backed	104	665,813		10,145		37,857		1,680		703,670		11,825
Total	141	$	778,714	$	12,583	$	59,597	$	2,837	$	838,311	$	15,420

Estimated Fair Values of Debt Securities by Contractual Maturity

The estimated fair values and amortized costs of available-for-sale and held-to-maturity debt securities by contractual maturity at December 31 are provided in the following table:

	December 31, 2022				December 31, 2021
(In thousands)	Fair Value		Amortized Cost		Fair Value		Amortized Cost
U.S. treasuries and government agencies:
One year or less	$	—	$	—	$	12,029	$	11,995
One to five years	93,622		100,926		56,510		56,492
Five to ten years	—		—		—		—
After ten years	—		—		—		—
State and municipal:
One year or less	8,694		8,783		12,821		12,709
One to five years	51,576		53,948		27,408		26,637
Five to ten years	28,806		34,042		42,960		42,661
After ten years	176,921		225,746		243,213		241,279
Mortgage-backed and asset-backed:
One year or less	7,622		7,704		9,272		9,239
One to five years	45,366		46,802		14,752		14,575
Five to ten years	303,697		335,285		388,918		390,569
After ten years	498,234		553,607		658,013		660,194
After ten years	—		—		—		—
Total available-for-sale debt securities	$	1,214,538	$	1,366,843	$	1,465,896	$	1,466,350

	December 31, 2022				December 31, 2021
(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	35,304		39,213		—		—
After ten years	184,819		220,239		—		—
Total held-to-maturity debt securities	$	220,123	$	259,452	$	—	$	—

Other Investments

Other investments are presented in the following table:

(In thousands)	2022		2021
Federal Reserve Bank stock, at cost	$	38,873	$	34,097
Federal Home Loan Bank of Atlanta stock, at cost	29,668		6,392
Other	677		677
Total other investments, at cost	$	69,218	$	41,166

Gross Realized Gains and Losses on All Investments

Gross realized gains and losses on all investments for the years ended December 31 are presented in the following table:

(In thousands)	2022		2021		2020
Gross realized gains from sales of investments available-for-sale	$	8	$	3,588	$	1,297
Gross realized losses from sales of investments available-for-sale	(393)		(3,478)		(1,068)
Net gains from calls of investments available-for-sale	40		102		238
Net investment securities gains/ (losses)	$	(345)	$	212	$	467