v3.26.1
INVESTMENT SECURITIES (Tables)
6 Months Ended
Jun. 30, 2026
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, 2026 and December 31, 2025.

Amortized
Cost
Gross Unrealized
Gains
Gross Unrealized
Losses
Fair
Value
Available for sale at June 30, 2026
U.S. Government-sponsored agency securities$83,118 $— $(11,379)$71,739 
State and municipal988,306 133 (95,307)893,132 
U.S. Government-sponsored mortgage-backed securities474,786 984 (65,551)410,219 
Foreign investment1,500 — — 1,500 
Corporate obligations7,989 — (187)7,802 
Total available for sale$1,555,699 $1,117 $(172,424)$1,384,392 

Amortized
Cost
Gross Unrealized
Gains
Gross Unrealized
Losses
Fair
Value
Available for sale at December 31, 2025
U.S. Government-sponsored agency securities$87,936 $— $(11,837)$76,099 
State and municipal993,911 225 (91,842)902,294 
U.S. Government-sponsored mortgage-backed securities482,702 1,600 (64,792)419,510 
Foreign investment1,500 — — 1,500 
Corporate obligations7,974 (276)7,699 
Total available for sale$1,574,023 $1,826 $(168,747)$1,407,102 

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, 2026 and December 31, 2025.

Amortized
Cost
Allowance for Credit LossesNet Carrying AmountGross Unrealized
Gains
Gross Unrealized
Losses
Fair
Value
Held to maturity at June 30, 2026
U.S. Government-sponsored agency securities$313,105 $— $313,105 $— $(43,984)$269,121 
State and municipal1,058,396 (245)1,058,151 489 (138,678)920,207 
U.S. Government-sponsored mortgage-backed securities536,428 — 536,428 — (71,813)464,615 
Total held to maturity$1,907,929 $(245)$1,907,684 $489 $(254,475)$1,653,943 

Amortized
Cost
Allowance for Credit LossesNet Carrying AmountGross Unrealized
Gains
Gross Unrealized
Losses
Fair
Value
Held to maturity at December 31, 2025
U.S. Government-sponsored agency securities$324,643 $— $324,643 $— $(46,693)$277,950 
State and municipal1,069,653 (245)1,069,408 868 (137,706)932,815 
U.S. Government-sponsored mortgage-backed securities577,488 — 577,488 — (69,966)507,522 
Total held to maturity$1,971,784 $(245)$1,971,539 $868 $(254,365)$1,718,287 
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 tables summarize the amortized cost of investment securities held to maturity at June 30, 2026 and December 31, 2025, aggregated by credit quality indicator.

June 30, 2026
U.S. Government-sponsored agency securities (1)
State and municipal
U.S. Government-sponsored mortgage-backed securities (1)
Total
Credit Rating:
Aaa$313,105 $73,616 $536,428 $923,149 
Aa1— 206,330 — 206,330 
Aa2— 161,487 — 161,487 
Aa3— 195,134 — 195,134 
A1— 59,625 — 59,625 
A2— 10,190 — 10,190 
A3— 10,153 — 10,153 
Non-rated— 341,861 — 341,861 
Total$313,105 $1,058,396 $536,428 $1,907,929 
(1) U.S. Government-sponsored agency securities and U.S. Government-sponsored 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.
December 31, 2025
U.S. Government-sponsored agency securities (1)
State and municipal
U.S. Government-sponsored mortgage-backed securities (1)
Total
Credit Rating:
Aaa$324,643 $75,598 $577,488 $977,729 
Aa1— 200,189 — 200,189 
Aa2— 172,127 — 172,127 
Aa3— 192,682 — 192,682 
A1— 59,631 — 59,631 
A2— 13,664 — 13,664 
A3— 6,670 — 6,670 
Non-rated— 349,092 — 349,092 
Total$324,643 $1,069,653 $577,488 $1,971,784 
(1) U.S. Government-sponsored agency securities and U.S. Government-sponsored 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, 2026 and December 31, 2025, 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, 2026
U.S. Government-sponsored agency securities$31 $(1)$71,708 $(11,378)$71,739 $(11,379)
State and municipal88,596 (1,334)782,596 (93,973)871,192 (95,307)
U.S. Government-sponsored mortgage-backed securities45,699 (339)297,367 (65,212)343,066 (65,551)
Corporate obligations985 (15)6,786 (172)7,771 (187)
Total investment securities available for sale$135,311 $(1,689)$1,158,457 $(170,735)$1,293,768 $(172,424)
Less than 12 Months12 Months or LongerTotal
Fair
Value
Gross
Unrealized
Losses
Fair
Value
Gross
Unrealized
Losses
Fair
Value
Gross
Unrealized
Losses
Investment securities available for sale at December 31, 2025
U.S. Government-sponsored agency securities$— $— $76,099 $(11,837)$76,099 $(11,837)
State and municipal5,468 (11)861,410 (91,830)866,878 (91,841)
U.S. Government-sponsored mortgage-backed securities4,885 (10)313,353 (64,783)318,238 (64,793)
Corporate obligations— — 6,676 (276)6,676 (276)
Total investment securities available for sale$10,353 $(21)$1,257,538 $(168,726)$1,267,891 $(168,747)

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, 2026
U.S. Government-sponsored agency securities$(11,379)13
State and municipal(95,307)594
U.S. Government-sponsored mortgage-backed securities(65,551)103
Corporate obligations(187)6
Total investment securities available for sale$(172,424)716 
Gross
Unrealized
Losses
Number of Securities
Investment securities available for sale at December 31, 2025
U.S. Government-sponsored agency securities$(11,837)12
State and municipal(91,841)587
U.S. Government-sponsored mortgage-backed securities(64,793)89
Corporate obligations(276)5
Total investment securities available for sale$(168,747)693 
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, 2026December 31, 2025
Investment securities available for sale reported at less than historical cost:
Historical cost$1,466,192 $1,436,638 
Fair value1,293,768 1,267,891 
Gross unrealized losses$(172,424)$(168,747)
Percentage of the Corporation's investment securities available for sale in an unrealized loss position93.5 %90.1 %
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, 2026 and December 31, 2025, 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, 2026
Due in one year or less$751 $747 $20,113 $19,993 
Due after one through five years21,701 21,387 109,135 106,569 
Due after five through ten years293,438 272,988 241,143 219,493 
Due after ten years765,023 679,051 1,001,110 843,273 
1,080,913 974,173 1,371,501 1,189,328 
U.S. Government-sponsored mortgage-backed securities474,786 410,219 536,428 464,615 
Total investment securities$1,555,699 $1,384,392 $1,907,929 $1,653,943 

Available for SaleHeld to Maturity
Amortized CostFair ValueAmortized CostFair Value
Maturity Distribution at December 31, 2025
Due in one year or less$— $— $7,014 $7,024 
Due after one through five years16,877 16,577 118,912 115,973 
Due after five through ten years241,803 227,493 228,224 210,125 
Due after ten years832,641 743,522 1,040,146 877,643 
1,091,321 987,592 1,394,296 1,210,765 
U.S. Government-sponsored mortgage-backed securities482,702 419,510 577,488 507,522 
Total investment securities$1,574,023 $1,407,102 $1,971,784 $1,718,287 
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, 2026 and 2025 are shown below.

Three Months Ended June 30,Six Months Ended June 30,
2026202520262025
Sales of investment securities available for sale:
Gross gains$— $— $— $— 
Gross losses— (1)— (8)
Net losses on sales of investment securities available for sale$— $(1)$— $(8)