The Company’s investment policy is designed primarily to provide and maintain liquidity, generate a favorable return on assets without incurring undue interest rate and credit risk and complement the Company’s lending activities.

During 2021, the Company transferred, at fair value, $244.8 million of U.S. government and agency securities from the available for sale classification to the held to maturity classification. The net unrealized after tax gain remained in AOCI and is amortized over the remaining life of the securities, offsetting the related amortization of discount or premium on the transferred securities. No gains or losses were recognized at the time of the transfer.

The following tables present the amortized cost and fair value of investment securities and the corresponding amounts of gross unrealized and unrecognized gains and losses, including the corresponding amounts of gross unrealized gains and losses on investment securities available for sale recognized in AOCI, at the dates indicated:


	December 31, 2023
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(Dollars in thousands)
Investment securities available for sale:
U.S. government and agency securities	$	16,047	$	—	$	(2,297)	$	13,750
Municipal securities	92,231		9		(12,715)		79,525
Residential CMO and MBS(1)	555,518		2,656		(46,125)		512,049
Commercial CMO and MBS(1)	538,910		88		(34,740)		504,258
Corporate obligations	7,745		2		(134)		7,613
Other asset-backed securities	17,336		31		(209)		17,158
Total	$	1,227,787	$	2,786	$	(96,220)	$	1,134,353


	December 31, 2023
	Amortized Cost		Gross Unrecognized Gains		Gross Unrecognized Losses		Fair Value
	(Dollars in thousands)
Investment securities held to maturity:
U.S. government and agency securities	$	151,075	$	—	$	(27,701)	$	123,374
Residential CMO and MBS(1)	267,204		—		(14,101)		253,103
Commercial CMO and MBS(1)	321,163		—		(35,190)		285,973
Total	$	739,442	$	—	$	(76,992)	$	662,450


	December 31, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
	(Dollars in thousands)
Investment securities available for sale:
U.S. government and agency securities	$	68,912	$	—	$	(5,053)	$	63,859
Municipal securities	171,087		172		(18,233)		153,026
Residential CMO and MBS(1)	479,473		—		(55,087)		424,386
Commercial CMO and MBS(1)	714,136		19		(49,734)		664,421
Corporate obligations	4,000		—		(166)		3,834
Other asset-backed securities	22,425		14		(522)		21,917
Total	$	1,460,033	$	205	$	(128,795)	$	1,331,443


	December 31, 2022
	Amortized Cost		Gross Unrecognized Gains		Gross Unrecognized Losses		Fair Value
	(Dollars in thousands)
Investment securities held to maturity:
U.S. government and agency securities	$	150,936	$	—	$	(33,585)	$	117,351
Residential CMO and MBS(1)	290,318		—		(17,440)		272,878
Commercial CMO and MBS(1)	325,142		—		(41,937)		283,205
Total	$	766,396	$	—	$	(92,962)	$	673,434

The following table presents the amortized cost and fair value of investment securities by contractual maturity at the date indicated. Actual maturities may differ from contractual maturities because certain borrowers have the right to call or prepay obligations with or without call or prepayment penalties.


	December 31, 2023
	Securities Available for Sale				Securities Held to Maturity
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
	(Dollars in thousands)
Due in one year or less	$	3,792	$	3,744	$	—	$	—
Due after one year through five years	2,602		2,557		—		—
Due after five years through ten years	39,711		36,331		93,260		78,570
Due after ten years	69,918		58,256		57,815		44,804
Total investment securities due at a single maturity date	116,023		100,888		151,075		123,374
MBS(1)	1,111,764		1,033,465		588,367		539,076
Total investment securities	$	1,227,787	$	1,134,353	$	739,442	$	662,450

There were no holdings of investment securities of any one issuer, other than the U.S. government and its agencies, in an amount greater than 10% of stockholders’ equity at December 31, 2023 and December 31, 2022.

The following tables present the gross unrealized losses and fair value of the Company’s investment securities available for sale for which an ACL on investment securities available for sale has not been recorded, aggregated by investment category and length of time the individual securities have been in a continuous unrealized loss position at the dates indicated:


	December 31, 2023
	Less than 12 Months				12 Months or Longer				Total
	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
	(Dollars in thousands)
U.S. government and agency securities	$	—	$	—	$	13,750	$	(2,297)	$	13,750	$	(2,297)
Municipal securities	3,548		(18)		71,458		(12,697)		75,006		(12,715)
Residential CMO and MBS(1)	—		—		358,316		(46,125)		358,316		(46,125)
Commercial CMO and MBS(1)	37,899		(228)		448,197		(34,512)		486,096		(34,740)
Corporate obligations	911		(20)		3,887		(114)		4,798		(134)
Other asset-backed securities	4,338		(22)		7,291		(187)		11,629		(209)
Total	$	46,696	$	(288)	$	902,899	$	(95,932)	$	949,595	$	(96,220)


	December 31, 2022
	Less than 12 Months				12 Months or Longer				Total
	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
	(Dollars in thousands)
U.S. government and agency securities	$	51,900	$	(2,031)	$	11,959	$	(3,022)	$	63,859	$	(5,053)
Municipal securities	$	82,580	$	(5,585)	$	40,945	$	(12,648)	123,525		(18,233)
Residential CMO and MBS(1)	217,949		(14,770)		206,437		(40,317)		424,386		(55,087)
Commercial CMO and MBS(1)	473,580		(16,971)		181,692		(32,763)		655,272		(49,734)
Corporate obligations	3,834		(166)		—		—		3,834		(166)
Other asset-backed securities	16,489		(510)		721		(12)		17,210		(522)
Total	$	846,332	$	(40,033)	$	441,754	$	(88,762)	$	1,288,086	$	(128,795)

The Company evaluated investment securities available for sale as of December 31, 2023 and December 31, 2022 and determined that any declines in fair value were attributable to changes in interest rates relative to where these investments fall within the yield curve and individual characteristics. Management monitors published credit ratings for adverse changes for all rated investment securities and none of these securities had a below investment grade credit rating as of both December 31, 2023 and December 31, 2022. In addition, the Company does not intend to sell these securities nor does the Company consider it more likely than not that it will be required to sell these securities before the recovery of the amortized cost basis, which may be upon maturity. Therefore, no ACL on investment securities available for sale was recorded as of December 31, 2023 and December 31, 2022.

The Company also evaluated investment securities held to maturity for current expected credit losses as of December 31, 2023 and December 31, 2022. There were no investment securities held to maturity classified as nonaccrual or past due as of December 31, 2023 and December 31, 2022 and all were issued by the U.S. government and its agencies and either explicitly or implicitly guaranteed by the U.S. government, highly rated by major credit rating agencies and had a long history of no credit losses. Accordingly, the Company did not measure expected credit losses on investment securities held to maturity since the historical credit loss information adjusted for current conditions and reasonable and supportable forecasts results in an expectation that nonpayment of the amortized cost basis is zero. Therefore, no ACL on investment securities held to maturity was recorded as of December 31, 2023 and December 31, 2022.

The following table presents the gross realized gains and losses on the sale of investment securities available for sale determined using the specific identification method for the dates indicated:


	Year ended December 31,
	2023		2022		2021
	(Dollars in thousands)
Gross realized gains	$	36	$	4	$	29
Gross realized losses	(12,267)		(260)		—
Net realized gains/(losses)	$	(12,231)	$	(256)	$	29


	December 31, 2023				December 31, 2022
	Amortized Cost		Fair Value		Amortized Cost		Fair Value
	(Dollars in thousands)
State and local governments public deposits	$	238,060	$	224,879	$	156,784	$	137,931
FRB	845,098		742,197		60,660		49,506
Securities sold under agreement to repurchase	—		—		63,685		55,836
Other securities pledged	54,636		49,032		54,910		48,358
Total	$	1,137,794	$	1,016,108	$	336,039	$	291,631

Accrued interest receivable excluded from the amortized cost of investment securities available for sale totaled $3.8 million and $4.8 million at December 31, 2023 and December 31, 2022, respectively. Accrued interest receivable excluded from the amortized cost on investment securities held to maturity totaled $2.3 million and $2.4 million at December 31, 2023 and December 31, 2022, respectively.

No amounts of accrued interest receivable on investment securities available for sale or held to maturity were reversed against interest income on investment securities during the years ended December 31, 2023, 2022, and 2021.

At December 31, 2022, as a member bank of Visa U.S.A., we held 6,549 shares of Visa Inc. Class B common stock. These shares had a carrying value of zero and were restricted from resale to non-member banks of Visa U.S.A. until their conversion into Class A (voting) shares upon the termination of Visa Inc.'s Covered Litigation escrow account. During the year ended December 31, 2023, the Company sold all shares of Visa Inc. Class B common stock and recognized a $1.6 million gain which is included in "Other income" on the Consolidated Statements of Income.