v3.26.3
INVESTMENT SECURITIES (Tables)
 9 Months Ended
Sep. 30, 2026
Investments, Debt and Equity Securities [Abstract]  
Schedule of Debt Securities, Available-for-sale
The following tables detail the amortized cost, allowance for credit losses and the estimated fair value of the Company's investments in available-for-sale and held-to-maturity debt securities. None of the Company's investments in debt securities are classified as trading.
September 30, 2026
(Dollars in thousands)Amortized CostGross
Unrealized
 Gain		Gross
Unrealized
 Loss		Allowance for Credit LossesFair
Value
Available-for-Sale Debt Securities
Collateralized mortgage obligations (CMO)$468,498 $— $86,683 $— $381,815 
Fannie Mae (FNMA) mortgage-backed securities (MBS)3,442,307 1 533,641 — 2,908,667 
Freddie Mac (FHLMC) MBS155,550 — 14,028 — 141,522 
Ginnie Mae (GNMA) MBS88,656 — 7,525 — 81,131 
Government-sponsored enterprises (GSE) agency notes218,370 — 40,388 — 177,982 
$4,373,381 $1 $682,265 $— $3,691,117 
Held-to-Maturity Debt Securities(1)
FNMA MBS$752,574 $— $144,015 $— $608,559 
State and political subdivisions173,153 — 11,228 5 161,920 
$925,727 $— $155,243 $5 $770,479 
(1)Held-to-maturity securities transferred from available-for-sale are included in held-to-maturity at fair value basis at the time of transfer. The amortized cost of transferred held-to-maturity securities included net unrealized losses of $71.9 million at September 30, 2026, which are offset in Accumulated other comprehensive loss. At the time of transfer, there was no allowance for credit loss on the available-for-sale securities. Subsequent to transfer, the securities were evaluated for credit loss.
December 31, 2025
(Dollars in thousands)Amortized CostGross
Unrealized
 Gain		Gross
Unrealized
 Loss		Allowance for Credit LossesFair
Value
Available-for-Sale Debt Securities
CMO$476,409 $416 $71,679 $— $405,146 
FNMA MBS3,167,210 2,289 384,092 — 2,785,407 
FHLMC MBS123,979 68 7,542 — 116,505 
GNMA MBS49,804 59 2,480 — 47,383 
GSE agency notes220,298 — 32,493 — 187,805 
$4,037,700 $2,832 $498,286 $— $3,542,246 
Held-to-Maturity Debt Securities(1)
FNMA MBS$788,439 $— $89,936 $— $698,503 
State and political subdivisions179,897 1,157 486 5 180,563 
$968,336 $1,157 $90,422 $5 $879,066 
(1)Held-to-maturity securities transferred from available-for-sale are included in held-to-maturity at fair value at the time of transfer. The amortized cost of transferred held-to-maturity securities included net unrealized losses of $83.4 million at December 31, 2025, which are offset in Accumulated other comprehensive loss. At the time of transfer, there was no allowance for credit loss on the available-for-sale securities. Subsequent to transfer, the securities were evaluated for credit loss.
Schedule of Debt Securities, Held-to-maturity
The following tables detail the amortized cost, allowance for credit losses and the estimated fair value of the Company's investments in available-for-sale and held-to-maturity debt securities. None of the Company's investments in debt securities are classified as trading.
September 30, 2026
(Dollars in thousands)Amortized CostGross
Unrealized
 Gain		Gross
Unrealized
 Loss		Allowance for Credit LossesFair
Value
Available-for-Sale Debt Securities
Collateralized mortgage obligations (CMO)$468,498 $— $86,683 $— $381,815 
Fannie Mae (FNMA) mortgage-backed securities (MBS)3,442,307 1 533,641 — 2,908,667 
Freddie Mac (FHLMC) MBS155,550 — 14,028 — 141,522 
Ginnie Mae (GNMA) MBS88,656 — 7,525 — 81,131 
Government-sponsored enterprises (GSE) agency notes218,370 — 40,388 — 177,982 
$4,373,381 $1 $682,265 $— $3,691,117 
Held-to-Maturity Debt Securities(1)
FNMA MBS$752,574 $— $144,015 $— $608,559 
State and political subdivisions173,153 — 11,228 5 161,920 
$925,727 $— $155,243 $5 $770,479 
(1)Held-to-maturity securities transferred from available-for-sale are included in held-to-maturity at fair value basis at the time of transfer. The amortized cost of transferred held-to-maturity securities included net unrealized losses of $71.9 million at September 30, 2026, which are offset in Accumulated other comprehensive loss. At the time of transfer, there was no allowance for credit loss on the available-for-sale securities. Subsequent to transfer, the securities were evaluated for credit loss.
December 31, 2025
(Dollars in thousands)Amortized CostGross
Unrealized
 Gain		Gross
Unrealized
 Loss		Allowance for Credit LossesFair
Value
Available-for-Sale Debt Securities
CMO$476,409 $416 $71,679 $— $405,146 
FNMA MBS3,167,210 2,289 384,092 — 2,785,407 
FHLMC MBS123,979 68 7,542 — 116,505 
GNMA MBS49,804 59 2,480 — 47,383 
GSE agency notes220,298 — 32,493 — 187,805 
$4,037,700 $2,832 $498,286 $— $3,542,246 
Held-to-Maturity Debt Securities(1)
FNMA MBS$788,439 $— $89,936 $— $698,503 
State and political subdivisions179,897 1,157 486 5 180,563 
$968,336 $1,157 $90,422 $5 $879,066 
(1)Held-to-maturity securities transferred from available-for-sale are included in held-to-maturity at fair value at the time of transfer. The amortized cost of transferred held-to-maturity securities included net unrealized losses of $83.4 million at December 31, 2025, which are offset in Accumulated other comprehensive loss. At the time of transfer, there was no allowance for credit loss on the available-for-sale securities. Subsequent to transfer, the securities were evaluated for credit loss.
Schedule of Maturities of Investment Securities Available-for-Sale and Held-to-Maturity
The scheduled maturities of available-for-sale debt securities at September 30, 2026 and December 31, 2025 are presented in the table below:
Available-for-Sale
AmortizedFair
(Dollars in thousands)CostValue
September 30, 2026 (1)
Within one year$93,132 $92,369 
After one year but within five years343,295 319,066 
After five years but within ten years611,063 525,963 
After ten years3,325,891 2,753,719 
$4,373,381 $3,691,117 
December 31, 2025 (1)
Within one year$46,226 $45,836 
After one year but within five years219,281 208,380 
After five years but within ten years471,231 422,496 
After ten years3,300,962 2,865,534 
$4,037,700 $3,542,246 
(1)Actual maturities could differ from contractual maturities.
The scheduled maturities of held-to-maturity debt securities at September 30, 2026 and December 31, 2025 are presented in the table below:
Held-to-Maturity
AmortizedFair
(Dollars in thousands)CostValue
September 30, 2026 (1)
Within one year$3,475 $3,440 
After one year but within five years20,046 19,379 
After five years but within ten years79,989 75,245 
After ten years822,217 672,415 
$925,727 $770,479 
December 31, 2025 (1)
Within one year$1,920 $1,918 
After one year but within five years21,180 21,166 
After five years but within ten years69,374 69,851 
After ten years875,862 786,131 
$968,336 $879,066 
(1)Actual maturities could differ from contractual maturities.
Schedule of Investment Securities' Gross Unrealized Losses and Fair Value by Investment Category
For debt securities in an unrealized loss position, the table below shows the gross unrealized losses and fair value by investment category and length of time that individual debt securities were in a continuous unrealized loss position at September 30, 2026.
Duration of Unrealized Loss Position
Less than 12 months12 months or longerTotal
FairUnrealizedFairUnrealizedFairUnrealized
(Dollars in thousands)ValueLossValueLossValueLoss
Available-for-sale debt securities:
CMO$47,071 $1,243 $334,744 $85,440 $381,815 $86,683 
FNMA MBS713,650 34,376 2,193,126 499,265 2,906,776 533,641 
FHLMC MBS48,161 1,829 93,361 12,199 141,522 14,028 
GNMA MBS49,609 3,011 31,522 4,514 81,131 7,525 
GSE agency notes— — 177,982 40,388 177,982 40,388 
$858,491 $40,459 $2,830,735 $641,806 $3,689,226 $682,265 
For debt securities in an unrealized loss position, the table below shows the gross unrealized losses and fair value by investment category and length of time that individual debt securities were in a continuous unrealized loss position at December 31, 2025.
Duration of Unrealized Loss Position
Less than 12 months12 months or longerTotal
FairUnrealizedFairUnrealizedFairUnrealized
(Dollars in thousands)ValueLossValueLossValueLoss
Available-for-sale debt securities:
CMO$— $— $394,776 $71,679 $394,776 $71,679 
FNMA MBS68,311 353 2,551,281 383,739 2,619,592 384,092 
FHLMC MBS7,978 58 103,510 7,484 111,488 7,542 
GNMA MBS4,323 93 34,290 2,387 38,613 2,480 
GSE agency notes— — 187,805 32,493 187,805 32,493 
$80,612 $504 $3,271,662 $497,782 $3,352,274 $498,286 
Schedule of Held-to-Maturity Credit Quality Indicators The following table summarizes the amortized cost of debt securities held-to-maturity as of September 30, 2026, aggregated by credit quality indicator:
(Dollars in thousands)FNMA MBSState and political subdivisions
A+ rated or higher$— $173,153 
Not rated752,574 — 
Ending balance$752,574 $173,153 
The following table summarizes the amortized cost of debt securities held-to-maturity as of December 31, 2025, aggregated by credit quality indicator:
(Dollars in thousands)FNMA MBSState and political subdivisions
A+ rated or higher$— $179,897 
Not rated788,439 — 
Ending balance$788,439 $179,897