v3.25.2
INVESTMENT SECURITIES (Tables)
 6 Months Ended
Jun. 30, 2025
Investments, Debt and Equity Securities [Abstract]  
Summary of Amortized Cost, Gross Unrealized Gains and Losses and Approximate Fair Value of Investment Securities
The following tables summarize the amortized cost, gross unrealized gains and losses and approximate fair value of investment securities available for sale as of June 30, 2025 and December 31, 2024.

Amortized
Cost		Gross Unrealized
Gains		Gross Unrealized
Losses		Fair
Value
Available for sale at June 30, 2025    
U.S. Government-sponsored agency securities$91,585 $— $13,346 $78,239 
State and municipal992,236 41 152,264 840,013 
U.S. Government-sponsored mortgage-backed securities503,417 1,172 75,128 429,461 
Corporate obligations10,967 — 550 10,417 
Total available for sale$1,598,205 $1,213 $241,288 $1,358,130 
Amortized
Cost		Gross Unrealized
Gains		Gross Unrealized
Losses		Fair
Value
Available for sale at December 31, 2024
U.S. Government-sponsored agency securities$95,462 $— $16,081 $79,381 
State and municipal996,541 19 133,386 863,174 
U.S. Government-sponsored mortgage-backed securities519,943 403 88,724 431,622 
Corporate obligations12,960 — 662 12,298 
Total available for sale$1,624,906 $422 $238,853 $1,386,475 
The following tables summarize the amortized cost, gross unrealized gains and losses, approximate fair value and allowance for credit losses on investment securities held to maturity as of June 30, 2025 and December 31, 2024.

Amortized
Cost		Allowance for Credit LossesNet Carrying AmountGross Unrealized
Gains		Gross Unrealized
Losses		Fair
Value
Held to maturity at June 30, 2025
U.S. Government-sponsored agency securities$334,970 $— $334,970 $— $52,156 $282,814 
State and municipal1,076,773 245 1,076,528 259 201,668 875,364 
U.S. Government-sponsored mortgage-backed securities609,828 — 609,828 — 82,266 527,562 
Foreign investment1,500 — 1,500 — — 1,500 
Total held to maturity$2,023,071 $245 $2,022,826 $259 $336,090 $1,687,240 


Amortized
Cost		Allowance for Credit LossesNet Carrying AmountGross Unrealized
Gains		Gross Unrealized
Losses		Fair
Value
Held to maturity at December 31, 2024
U.S. Government-sponsored agency securities$345,531 $— $345,531 $— $63,112 $282,419 
State and municipal1,085,921 245 1,085,676 299 185,784 900,436 
U.S. Government-sponsored mortgage-backed securities641,513 — 641,513 — 102,343 539,170 
Foreign investment1,500 — 1,500 — 5 1,495 
Total held to maturity$2,074,465 $245 $2,074,220 $299 $351,244 $1,723,520 
Summary of Amortized Cost of Investment Securities Held to Maturity Aggregated by Credit Quality Indicator
On a quarterly basis, the Corporation monitors the credit quality of investment securities held to maturity through the use of credit ratings. The following table summarizes the amortized cost of investment securities held to maturity at June 30, 2025 and December 31, 2024, aggregated by credit quality indicator.
June 30, 2025
U.S. Government-sponsored agency securities (1)
State and municipal
U.S. Government-sponsored mortgage-backed securities (1)
Foreign investmentTotal
Credit Rating:
Aaa$334,970 $96,739 $609,828 $— $1,041,537 
Aa1— 179,548 — — 179,548 
Aa2— 176,970 — — 176,970 
Aa3— 183,941 — — 183,941 
A1— 65,652 — — 65,652 
A2— 20,325 — — 20,325 
Non-rated— 353,598 — 1,500 355,098 
Total$334,970 $1,076,773 $609,828 $1,500 $2,023,071 

December 31, 2024
U.S. Government-sponsored agency securities (1)
State and municipal
U.S. Government-sponsored mortgage-backed securities (1)
Foreign investmentTotal
Credit Rating:
Aaa$345,531 $120,801 $641,513 $— $1,107,845 
Aa1— 148,923 — — 148,923 
Aa2— 184,341 — — 184,341 
Aa3— 185,166 — — 185,166 
A1— 65,665 — — 65,665 
A2— 20,317 — — 20,317 
Non-rated— 360,708 — 1,500 362,208 
Total$345,531 $1,085,921 $641,513 $1,500 $2,074,465 

(1) U.S. Government agency securities and U.S. Government mortgage-backed securities are included within the Aaa credit rating category due to their explicit or implicit government guarantees, which provide a high level of assurance regarding the timely collection of principal and interest payments.
Summary of Investment Securities in a Continuous Unrealized Loss Position
The following tables summarize, as of June 30, 2025 and December 31, 2024, investment securities available for sale in an unrealized loss position for which an allowance for credit losses has not been recorded, aggregated by security type and length of time in a continuous unrealized loss position.
Less than 12 Months12 Months or LongerTotal
Fair
Value		Gross
Unrealized
Losses		Fair
Value		Gross
Unrealized
Losses		Fair
Value		Gross
Unrealized
Losses
Investment securities available for sale at June 30, 2025
U.S. Government-sponsored agency securities$— $— $78,239 $13,346 $78,239 $13,346 
State and municipal9,675 580 828,677 151,684 838,352 152,264 
U.S. Government-sponsored mortgage-backed securities43,049 512 315,870 74,616 358,919 75,128 
Corporate obligations— — 10,386 550 10,386 550 
Total investment securities available for sale$52,724 $1,092 $1,233,172 $240,196 $1,285,896 $241,288 
Less than 12 Months12 Months or LongerTotal
Fair
Value		Gross
Unrealized
Losses		Fair
Value		Gross
Unrealized
Losses		Fair
Value		Gross
Unrealized
Losses
Investment securities available for sale at December 31, 2024
U.S. Government-sponsored agency securities$— $— $79,381 $16,081 $79,381 $16,081 
State and municipal40,398 2,115 820,663 131,271 861,061 133,386 
U.S. Government-sponsored mortgage-backed securities82,724 1,660 318,310 87,064 401,034 88,724 
Corporate obligations— — 12,268 662 12,268 662 
Total investment securities available for sale$123,122 $3,775 $1,230,622 $235,078 $1,353,744 $238,853 
The following tables summarize investment securities available for sale in an unrealized loss position for which an allowance for credit losses has not been recorded, aggregated by security type and the number of securities in the portfolio as of the dates indicated.

Gross
Unrealized
Losses		Number of Securities
Investment securities available for sale at June 30, 2025
U.S. Government-sponsored agency securities$13,346 12
State and municipal152,264 609
U.S. Government-sponsored mortgage-backed securities75,128 110
Corporate obligations550 9
Total investment securities available for sale$241,288 740 
Gross
Unrealized
Losses		Number of Securities
Investment securities available for sale at December 31, 2024
U.S. Government-sponsored agency securities$16,081 12
State and municipal133,386 611
U.S. Government-sponsored mortgage-backed securities88,724 127
Corporate obligations662 10
Total investment securities available for sale$238,853 760 
Summary of Investments in Debt and Equity Securities Reported in the Financial Statements at an Amount Less Than Their Historical Cost
Certain investment securities available for sale are reported in the financial statements at an amount less than their historical cost as indicated in the table below.
June 30, 2025December 31, 2024
Investments available for sale reported at less than historical cost:  
Historical cost$1,527,184 $1,592,597 
Fair value1,285,896 1,353,744 
Gross unrealized losses$241,288 $238,853 
Percentage of the Corporation's investment securities available for sale in an unrealized loss position94.7 %97.6 %
Summary of Amortized Cost and Fair Value of Available for Sale Securities and Held to Maturity Securities by Contractual Maturity
The amortized cost and fair value of investment securities available for sale and held to maturity at June 30, 2025 and December 31, 2024, by contractual maturity are shown below. Expected maturities will differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. Securities not due at a single maturity are shown separately.

Available for SaleHeld to Maturity
Amortized CostFair ValueAmortized CostFair Value
Maturity Distribution at June 30, 2025
Due in one year or less$— $— $4,878 $4,877 
Due after one through five years12,965 12,580 121,851 117,859 
Due after five through ten years205,079 185,363 196,082 175,327 
Due after ten years876,744 730,726 1,090,432 861,615 
 1,094,788 928,669 1,413,243 1,159,678 
U.S. Government-sponsored mortgage-backed securities503,417 429,461 609,828 527,562 
Total investment securities$1,598,205 $1,358,130 $2,023,071 $1,687,240 
Available for SaleHeld to Maturity
Amortized CostFair ValueAmortized CostFair Value
Maturity Distribution at December 31, 2024
Due in one year or less$1,800 $1,795 $5,268 $5,254 
Due after one through five years12,189 11,857 124,004 117,999 
Due after five through ten years168,338 151,467 174,533 154,533 
Due after ten years922,636 789,734 1,129,147 906,564 
 1,104,963 954,853 1,432,952 1,184,350 
U.S. Government-sponsored mortgage-backed securities519,943 431,622 641,513 539,170 
Total investment securities$1,624,906 $1,386,475 $2,074,465 $1,723,520 
Summary of Gross Gains and Losses on Sales and Redemptions of Available for Sale Securities
Gross gains and losses on the sales of investment securities available for sale for the three and six months ended June 30, 2025 and 2024 are shown below.
Three Months Ended June 30,Six Months Ended June 30,
2025202420252024
Sales and redemptions of investment securities available for sale:  
Gross gains$— $— $— $— 
Gross losses(1)(49)(8)(51)
Net gains (losses) on sales and redemptions of investment securities available for sale$(1)$(49)$(8)$(51)