v3.26.1
Securities (Tables)
 3 Months Ended
Mar. 31, 2026
Investments, Debt and Equity Securities [Abstract]  
Schedule of Comparison of Securities by Type
A summary comparison of securities by type at March 31, 2026 and December 31, 2025 is shown below. 

 March 31, 2026December 31, 2025
(in thousands)Amortized CostGross
Unrealized Gains		Gross
Unrealized Losses		Fair ValueAmortized CostGross Unrealized GainsGross
Unrealized Losses		Fair Value
Available for sale:        
U.S. Treasuries$73,940 $— $(33)$73,907 $98,123 $26 $— $98,149 
Corporate debt securities5,480 — (91)5,389 6,500 — (51)6,449 
Municipal bonds14,868 46 (973)13,941 21,211 218 (373)21,056 
Collateralized mortgage obligations494,435 474 (3,989)490,920 301,685 1,232 (336)302,581 
Mortgage-backed securities270,741 759 (1,744)269,756 246,620 2,085 (348)248,357 
Total available for sale securities$859,464 $1,279 $(6,830)$853,913 $674,139 $3,561 $(1,108)$676,592 
Held to maturity:        
U.S. Government Agencies$267,842 $— $(53,750)$214,092 $267,626 $— $(51,627)$215,999 
Corporate debt securities55,247 8 (3,768)51,487 55,199 8 (3,112)52,095 
Total held to maturity securities$323,089 $8 $(57,518)$265,579 $322,825 $8 $(54,739)$268,094 
Schedule of Investments Classified by Contractual Maturity Date
The scheduled maturities of securities at March 31, 2026, by contractual maturity, are shown below. Actual maturities may differ from contractual maturities due to calls or prepayments. Mortgage-backed securities are not due at a single maturity because of amortization and potential prepayment of the underlying mortgages. For this reason, they are presented separately in the maturity table below:
 
 At March 31, 2026
(in thousands)Amortized CostFair Value
Available for sale:  
Due in one year or less$75,129 $75,077 
Due after one year through five years8,868 8,697 
Due after five years through 10 years8,643 7,997 
Over 10 years1,648 1,466 
Subtotal94,288 93,237 
Collateralized mortgage obligations494,435 490,920 
Mortgage-backed securities270,741 269,756 
Total available for sale securities$859,464 $853,913 
Held to maturity:  
Due in one year or less$— $— 
Due after one year through five years60,479 55,865 
Due after five years through 10 years101,929 89,166 
Over 10 years160,681 120,548 
Total held to maturity securities$323,089 $265,579 
Schedule of Unrealized Loss on Investments
The following is a summary of the fair value of securities with gross unrealized losses and an aging of those gross unrealized losses at March 31, 2026.

  At March 31, 2026 
 Less Than 12 Months12 Months or MoreTotal
(in thousands)Number
of Securities		Fair ValueGross
Unrealized
Losses		Number
of Securities		Fair ValueGross
Unrealized
Losses		Number
of Securities		Fair ValueGross
Unrealized Losses
Available for sale:         
U.S. Treasuries6 $73,907 $(33)— $— $— 6 $73,907 $(33)
Corporate debt securities2 1,980 (20)3 2,429 (71)5 4,409 (91)
Municipal bonds42 7,463 (208)26 5,679 (765)68 13,142 (973)
Collateralized mortgage obligations86 400,627 (3,989)— — — 86 400,627 (3,989)
Mortgage-backed securities44 147,023 (1,429)6 12,282 (315)50 159,305 (1,744)
Total available for sale securities180 $631,000 $(5,679)35 $20,390 $(1,151)215 $651,390 $(6,830)
Held to maturity:         
U.S. Government Agencies— $— $— 29 $214,092 $(53,750)29 $214,092 $(53,750)
Corporate debt securities2 1,795 (148)54 49,368 (3,620)56 51,163 (3,768)
Total held to maturity securities2 $1,795 $(148)83 $263,460 $(57,370)85 $265,255 $(57,518)

The following is a summary of the fair value of securities with gross unrealized losses and an aging of those gross unrealized losses at December 31, 2025. 

  At December 31, 2025 
 Less Than 12 Months12 Months or MoreTotal
(in thousands)Number
of Securities		Fair ValueGross
Unrealized
Losses		Number
of Securities		Fair ValueGross
Unrealized Losses		Number
of Securities		Fair ValueGross
Unrealized Losses
Available for sale:         
U.S. Treasuries2 $19,646 $— — $— $— 2 $19,646 $— 
Corporate debt securities2 1,989 (11)4 3,460 (40)6 5,449 (51)
Municipal bonds— — — 28 6,261 (373)28 6,261 (373)
Collateralized mortgage obligations31 137,608 (336)— — — 31 137,608 (336)
Mortgage-backed securities14 40,812 (130)10 27,421 (218)24 68,233 (348)
Total available for sale securities49 $200,055 $(477)42 $37,142 $(631)91 $237,197 $(1,108)
Held to maturity:
U.S. Government Agencies— $— $— 29 $215,999 $(51,627)29 $215,999 $(51,627)
Corporate debt securities2 1,805 (136)54 49,965 (2,976)56 51,770 (3,112)
Total held to maturity securities2 $1,805 $(136)83 $265,964 $(54,603)85 $267,769 $(54,739)
Schedule of Exposure to Investment Securities Issuers that Exceeded 10% of Shareholders' Equity
At March 31, 2026, First Guaranty's exposure to bond issuers that exceeded 10% of shareholders' equity is below: 

 At March 31, 2026
(in thousands)Amortized CostFair Value
U.S. Government Treasuries (U.S.)$73,940 $73,907 
Federal Home Loan Bank (FHLB)32,434 27,172 
Federal Home Loan Mortgage Corporation (Freddie Mac-FHLMC)101,889 76,600 
Federal Farm Credit Bank (FFCB)139,839 116,542 
Government National Mortgage Association (Ginnie Mae-GNMA)756,634 752,209 
Total$1,104,736 $1,046,430