Investment Securities

3 Months Ended

Mar. 31, 2023

Investments, Debt and Equity Securities [Abstract]

Investment Securities

Investment securities:

The following tables summarize the amortized cost, allowance for credit losses and fair value of the available-for-sale debt securities and the corresponding amounts of unrealized gains and losses recognized in accumulated other comprehensive loss at March 31, 2023 and December 31, 2022:  

	March 31, 2023
	Amortized cost		Gross unrealized gains		Gross unrealized losses		Allowance for credit losses for investments		Fair Value
Investment Securities
Available-for-sale debt securities
U.S. government agency securities	$	45,176	$	—	$	(4,248)	$	—	$	40,928
Mortgage-backed securities - residential	1,197,702		—		(172,314)		—		1,025,388
Mortgage-backed securities - commercial	18,979		—		(1,256)		—		17,723
Municipal securities	295,010		967		(24,983)		—		270,994
U.S. Treasury securities	113,403		—		(4,580)		—		108,823
Corporate securities	8,000		—		(851)		—		7,149
Total	$	1,678,270	$	967	$	(208,232)	$	—	$	1,471,005

	December 31, 2022
	Amortized cost		Gross unrealized gains		Gross unrealized losses		Allowance for credit losses for investments		Fair Value
Investment Securities
Available-for-sale debt securities
U.S. government agency securities	$	45,167	$	—	$	(5,105)	$	—	$	40,062
Mortgage-backed securities - residential	1,224,522		—		(190,329)		—		1,034,193
Mortgage-backed securities - commercial	19,209		—		(1,565)		—		17,644
Municipal securities	295,375		458		(31,413)		—		264,420
U.S. Treasury securities	113,301		—		(5,621)		—		107,680
Corporate securities	8,000		—		(813)		—		7,187
Total	$	1,705,574	$	458	$	(234,846)	$	—	$	1,471,186

The components of amortized cost for debt securities on the consolidated balance sheets excludes accrued interest receivable since the Company elected to present accrued interest receivable separately on the consolidated balance sheets. As of March 31, 2023 and December 31, 2022, total accrued interest receivable on debt securities was $5,399 and $5,470, respectively.

Securities pledged at March 31, 2023 and December 31, 2022 had carrying amounts of $1,184,836 and $1,191,021, respectively, and were pledged to secure a Federal Reserve Bank line of credit, public deposits and repurchase agreements.

There were no holdings of debt securities of any one issuer, other than U.S. Government sponsored enterprises, in an amount greater than 10% of shareholders' equity during any period presented.

Investment securities transactions are recorded as of the trade date. As of March 31, 2023, there were $245 in trade date payables that related to purchases settled after period end. There were no such trade date payables as of December 31, 2022.

The amortized cost and fair value of debt securities by contractual maturity as of March 31, 2023 and December 31, 2022 are shown below. Maturities may differ from contractual maturities in mortgage-backed securities because the mortgage underlying the security may be called or repaid without any penalties. Therefore, mortgage-backed securities are not included in the maturity categories in the following summary.

	March 31,				December 31,
	2023				2022
	Available-for-sale				Available-for-sale
	Amortized cost		Fair value		Amortized cost		Fair value
Due in one year or less	$	34,965	$	34,270	$	4,277	$	4,225
Due in one to five years	138,189		130,585		161,556		152,181
Due in five to ten years	58,876		56,982		61,290		57,859
Due in over ten years	229,559		206,057		234,720		205,084
	461,589		427,894		461,843		419,349
Mortgage-backed securities - residential	1,197,702		1,025,388		1,224,522		1,034,193
Mortgage-backed securities - commercial	18,979		17,723		19,209		17,644
Total debt securities	$	1,678,270	$	1,471,005	$	1,705,574	$	1,471,186

Sales and other dispositions of available-for-sale securities were as follows:

	Three Months Ended March 31,
	2023		2022
Proceeds from sales	$	—	$	—
Proceeds from maturities, prepayments and calls	26,827		57,443
Gross realized gains	—		2
Gross realized losses	—		—

The following tables show gross unrealized losses for which an allowance for credit losses has not been recorded at March 31, 2023 and December 31, 2022, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position:

	March 31, 2023
	Less than 12 months				12 months or more				Total
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
U.S. government agency securities	$	4,014	$	(94)	$	36,913	$	(4,154)	$	40,927	$	(4,248)
Mortgage-backed securities - residential	101,194		(4,425)		924,189		(167,889)		1,025,383		(172,314)
Mortgage-backed securities - commercial	11,311		(740)		6,415		(516)		17,726		(1,256)
Municipal securities	43,100		(1,872)		161,743		(23,111)		204,843		(24,983)
U.S. Treasury securities	60,669		(1,276)		48,154		(3,304)		108,823		(4,580)
Corporate securities	946		(55)		6,281		(796)		7,227		(851)
Total	$	221,234	$	(8,462)	$	1,183,695	$	(199,770)	$	1,404,929	$	(208,232)

	December 31, 2022
	Less than 12 months				12 months or more				Total
	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized loss
U.S. government agency securities	$	23,791	$	(2,802)	$	16,271	$	(2,303)	$	40,062	$	(5,105)
Mortgage-backed securities - residential	316,656		(32,470)		717,533		(157,859)		1,034,189		(190,329)
Mortgage-backed securities - commercial	11,104		(968)		6,541		(597)		17,645		(1,565)
Municipal securities	196,419		(26,811)		36,726		(4,602)		233,145		(31,413)
U.S. Treasury securities	94,248		(4,122)		13,434		(1,499)		107,682		(5,621)
Corporate securities	4,008		(492)		3,270		(321)		7,278		(813)
Total	$	646,226	$	(67,665)	$	793,775	$	(167,181)	$	1,440,001	$	(234,846)

As of March 31, 2023 and December 31, 2022, the Company’s debt securities portfolio consisted of 506 and 503 securities, 409 and 454 of which were in an unrealized loss position, respectively.

During the three months ended March 31, 2023, the Company's available-for-sale debt securities portfolio unrealized value increased $27,123 to an unrealized loss position of $207,265 from an unrealized loss position of $234,388 as of December 31, 2022. During the three months ended March 31, 2022, the Company's available-for-sale debt securities portfolio unrealized value declined $105,660 to an unrealized loss position of $100,933 from an unrealized gain position of $4,727 as of December 31, 2021.

The majority of the investment portfolio was either government guaranteed, an issuance of a government sponsored entity or highly rated by major credit rating agencies and the Company has historically not recorded any losses associated with these investments. Municipal securities with market values below amortized cost at March 31, 2023 were reviewed for material credit events and/or rating downgrades with individual credit reviews performed. The issuers of these debt securities continue to make timely principal and interest payments under the contractual terms of the securities and the issuers will continue to be observed as a part of the Company’s ongoing credit monitoring. As such, as of March 31, 2023 and December 31, 2022, it was determined that all available-for-sale debt securities that experienced a decline in fair value below amortized cost basis were due to noncredit-related factors. Further, the Company does not intend to sell those available-for-sale securities that have an unrealized loss as of March 31, 2023, and it is not likely that the Company will be required to sell the securities before recovery of their amortized cost basis. Therefore, there was no provision for credit losses recognized on available-for-sale debt securities during the three months ended March 31, 2023 or 2022.

Equity Securities

As of March 31, 2023 and December 31, 2022, the Company had $3,059 and $2,990, in marketable equity securities recorded at fair value, respectively. The Company had equity securities without readily determinable market value included in other assets on the consolidated balance sheets with carrying amounts of $22,483 and $22,496 at March 31, 2023 and December 31, 2022, respectively. Additionally, the Company had $43,369 and $58,641 of Federal Home Loan Bank stock carried at cost at March 31, 2023 and December 31, 2022, respectively, included separately from the other equity securities discussed above.

The change in the fair value of equity securities and sale of equity securities with readily determinable fair values resulted in a net gain of $69 and a net loss of $154 for the three months ended March 31, 2023 and 2022, respectively.