v3.26.1
Investment Securities (Tables)
 6 Months Ended
Jun. 30, 2026
Investments, Debt and Equity Securities [Abstract]  
Schedule of Debt Securities, Available-for-sale
The amortized cost, fair value and allowance for credit losses of investment securities that are classified as AFS are as follows:

(In thousands)Amortized
Cost		Allowance
for Credit Losses		Gross Unrealized
Gains		Gross Unrealized
(Losses)		Estimated Fair
Value
Available-for-sale
June 30, 2026
U.S. Government agencies$45,008 $— $4 $(587)$44,425 
Mortgage-backed securities2,254,293 — 665 (193,198)2,061,760 
State and political subdivisions1,030,971 — 32 (165,536)865,467 
Other securities109,254 — 3 (3,728)105,529 
Total AFS$3,439,526 $— $704 $(363,049)$3,077,181 
December 31, 2025
U.S. Government agencies$47,786 $— $6 $(620)$47,172 
Mortgage-backed securities2,385,646 — 6,072 (189,760)2,201,958 
State and political subdivisions1,046,121 — 42 (187,092)859,071 
Other securities163,256 — 209 (5,445)158,020 
Total AFS$3,642,809 $— $6,329 $(382,917)$3,266,221 
Schedule of Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value
The following table summarizes the Company’s AFS investments in an unrealized loss position for which an allowance for credit loss has not been recorded as of June 30, 2026 and December 31, 2025, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position:

Less Than 12 Months12 Months or MoreTotal
(In thousands)Estimated
Fair
Value		Gross
Unrealized
Losses		Estimated
Fair
Value		Gross
Unrealized
Losses		Estimated
Fair
Value		Gross
Unrealized
Losses
Available-for-sale
June 30, 2026
U.S. Government agencies$— $— $43,291 $(587)$43,291 $(587)
Mortgage-backed securities210,440 (871)1,559,771 (192,327)1,770,211 (193,198)
State and political subdivisions7,227 (14)835,710 (165,522)842,937 (165,536)
Other securities9,936 (16)81,411 (3,712)91,347 (3,728)
Total AFS$227,603 $(901)$2,520,183 $(362,148)$2,747,786 $(363,049)
December 31, 2025
U.S. Government agencies$2,247 $(17)$43,767 $(603)$46,014 $(620)
Mortgage-backed securities15,305 (74)1,672,723 (189,686)1,688,028 (189,760)
State and political subdivisions5,757 (969)824,265 (186,123)830,022 (187,092)
Other securities— — 96,176 (5,445)96,176 (5,445)
Total AFS$23,309 $(1,060)$2,636,931 $(381,857)$2,660,240 $(382,917)
Schedule of Debt Securities, Allowance for Credit Loss Activity in the allowance for credit losses by investment security type for the three and six months ended June 30, 2025 on the Company’s HTM securities portfolio was as follows:
(In thousands)State and Political SubdivisionsOther
Securities		Total
Three Months Ended June 30, 2025
Held-to-maturity
Beginning balance, April 1, 2025$171 $3,043 $3,214 
Provision for credit loss expense— — — 
Net increase (decrease) in allowance on previously impaired securities31 (31)— 
Ending balance, June 30, 2025$202 $3,012 $3,214 
Six Months Ended June 30, 2025
Held-to-maturity
Beginning balance, January 1, 2025$196 $3,018 $3,214 
Provision for credit loss expense— — — 
Net increase (decrease) in allowance on previously impaired securities6 (6)— 
Ending balance, June 30, 2025$202 $3,012 $3,214 
Schedule of Income Earned on Securities
Income earned on securities for the three and six months ended June 30, 2026 and 2025, is as follows:

Three Months Ended
June 30,		Six Months Ended
June 30,
(In thousands)2026202520262025
Taxable:
Held-to-maturity$— $10,224 $— $20,623 
Available-for-sale25,472 21,009 51,783 42,194 
Non-taxable:
Held-to-maturity— 10,052 — 20,103 
Available-for-sale5,541 5,613 11,112 11,235 
Total$31,013 $46,898 $62,895 $94,155 
Schedule of Amortized Cost and Estimated Fair Value by Maturity of Securities
The amortized cost and estimated fair value by maturity of AFS securities as of June 30, 2026 are shown in the following table. Securities are classified according to their contractual maturities without consideration of principal amortization, potential prepayments or call options. Accordingly, actual maturities may differ from contractual maturities. 

Available-for-Sale
(In thousands)Amortized
Cost		Fair
Value
One year or less$1,129 $1,122 
After one through five years83,447 82,662 
After five through ten years93,730 89,529 
After ten years1,006,734 841,915 
Securities not due on a single maturity date2,254,293 2,061,760 
Other securities (no maturity)193 193 
Total$3,439,526 $3,077,181