XML 29 R22.htm IDEA: XBRL DOCUMENT
v3.25.3

Securities (Tables) | 9 Months Ended
--- | ---
Sep. 30, 2025
Cash and Cash Equivalents [Abstract] |
Summary of Available-for-Sale Securities | The amortized cost, related gross unrealized gains and losses, allowance for credit losses and the fair value of available-for-sale securities are as follows (dollars in thousands):
|  | September 30, 2025 |
|  |  |  |  | Gross |  |  | Gross |  |  |  |
|  | Amortized |  |  | Unrealized |  |  | Unrealized |  |  | Estimated |
|  | Cost Basis |  |  | Holding Gains |  |  | Holding Losses |  |  | Fair Value |
Securities available-for-sale: |  |  |  |  |  |  |  |  |  |  |  |
U.S. Treasury securities |  | $ | 102,865 |  |  | $ | 2 |  |  | $ | (897 | ) |  | $ | 101,970 |
Obligations of states and political subdivisions |  |  | 1,859,132 |  |  |  | 8,751 |  |  |  | (133,972 | ) |  |  | 1,733,911 |
Residential mortgage-backed securities |  |  | 2,737,201 |  |  |  | 5,622 |  |  |  | (272,025 | ) |  |  | 2,470,798 |
Commercial mortgage-backed securities |  |  | 849,026 |  |  |  | 8,580 |  |  |  | (3,418 | ) |  |  | 854,188 |
Corporate bonds and other |  |  | 103,544 |  |  |  | 20 |  |  |  | (3,618 | ) |  |  | 99,946 |
Total securities available-for-sale |  | $ | 5,651,768 |  |  | $ | 22,975 |  |  | $ | (413,930 | ) |  | $ | 5,260,813 |
|  | September 30, 2024 |
|  |  |  |  | Gross |  |  | Gross |  |  |  |
|  | Amortized |  |  | Unrealized |  |  | Unrealized |  |  | Estimated |
|  | Cost Basis |  |  | Holding Gains |  |  | Holding Losses |  |  | Fair Value |
Securities available-for-sale: |  |  |  |  |  |  |  |  |  |  |  |
U.S. Treasury securities |  | $ | 298,671 |  |  | $ | 14 |  |  | $ | (5,671 | ) |  | $ | 293,014 |
Obligations of states and political subdivisions |  |  | 1,586,300 |  |  |  | 699 |  |  |  | (115,516 | ) |  |  | 1,471,483 |
Residential mortgage-backed securities |  |  | 2,712,305 |  |  |  | 1,655 |  |  |  | (290,030 | ) |  |  | 2,423,930 |
Commercial mortgage-backed securities |  |  | 320,685 |  |  |  | 1,946 |  |  |  | (5,795 | ) |  |  | 316,836 |
Corporate bonds and other |  |  | 112,163 |  |  |  | 59 |  |  |  | (5,186 | ) |  |  | 107,036 |
Total securities available-for-sale |  | $ | 5,030,124 |  |  | $ | 4,373 |  |  | $ | (422,198 | ) |  | $ | 4,612,299 |
|  | December 31, 2024 |
|  |  |  |  | Gross |  |  | Gross |  |  |  |
|  | Amortized |  |  | Unrealized |  |  | Unrealized |  |  | Estimated |
|  | Cost Basis |  |  | Holding Gains |  |  | Holding Losses |  |  | Fair Value |
Securities available-for-sale: |  |  |  |  |  |  |  |  |  |  |  |
U.S. Treasury securities |  | $ | 278,155 |  |  | $ | 2 |  |  | $ | (4,595 | ) |  | $ | 273,562 |
Obligations of states and political subdivisions |  |  | 1,578,749 |  |  |  | 338 |  |  |  | (138,842 | ) |  |  | 1,440,245 |
Residential mortgage-backed securities |  |  | 2,729,096 |  |  |  | 184 |  |  |  | (378,746 | ) |  |  | 2,350,534 |
Commercial mortgage-backed securities |  |  | 457,311 |  |  |  | 99 |  |  |  | (9,658 | ) |  |  | 447,752 |
Corporate bonds and other |  |  | 111,994 |  |  |  | 50 |  |  |  | (6,378 | ) |  |  | 105,666 |
Total securities available-for-sale |  | $ | 5,155,305 |  |  | $ | 673 |  |  | $ | (538,219 | ) |  | $ | 4,617,759 |
Carrying Value and Estimated Fair Value of Available-for-Sale Securities | The carrying value and estimated fair value of available-for-sale securities at September 30, 2025, by contractual and expected maturity, are shown below (dollars in thousands):
|  | Carrying |  |  | Estimated |
|  | Value |  |  | Fair Value |
Due within one year |  | $ | 225,746 |  |  | $ | 223,945 |
Due after one year through five years |  |  | 2,493,891 |  |  |  | 2,383,120 |
Due after five years through ten years |  |  | 2,145,923 |  |  |  | 1,966,228 |
Due after ten years |  |  | 786,208 |  |  |  | 687,520 |
Total |  | $ | 5,651,768 |  |  | $ | 5,260,813 |
Continuous Unrealized-Loss Position of Available-for-Sale Securities | The following tables disclose as of September 30, 2025 and 2024, and December 31, 2024, the Company’s investment securities that have been in a continuous unrealized-loss position for less than 12 months and for 12 or more months (dollars in thousands):
|  | Less than 12 Months |  |  | 12 Months or Longer |  |  | Total |
September 30, 2025 |  | Fair Value |  |  | Unrealized Loss |  |  | Fair Value |  |  | Unrealized Loss |  |  | Fair Value |  |  | Unrealized Loss |
U.S. Treasury securities |  | $ | 1,000 |  |  | $ | — |  |  | $ | 99,476 |  |  | $ | (897 | ) |  | $ | 100,476 |  |  | $ | (897 | )
Obligations of states and political subdivisions |  |  | 21,278 |  |  |  | (854 | ) |  |  | 1,344,598 |  |  |  | (133,118 | ) |  |  | 1,365,876 |  |  |  | (133,972 | )
Residential mortgage-backed securities |  |  | 125,497 |  |  |  | (450 | ) |  |  | 2,042,826 |  |  |  | (271,575 | ) |  |  | 2,168,323 |  |  |  | (272,025 | )
Commercial mortgage-backed securities |  |  | 66,851 |  |  |  | (74 | ) |  |  | 166,330 |  |  |  | (3,344 | ) |  |  | 233,181 |  |  |  | (3,418 | )
Corporate bonds and other |  |  | — |  |  |  | — |  |  |  | 82,982 |  |  |  | (3,618 | ) |  |  | 82,982 |  |  |  | (3,618 | )
Total |  | $ | 214,626 |  |  | $ | (1,378 | ) |  | $ | 3,736,212 |  |  | $ | (412,552 | ) |  | $ | 3,950,838 |  |  | $ | (413,930 | )
|  | Less than 12 Months |  |  | 12 Months or Longer |  |  | Total |
September 30, 2024 |  | Fair Value |  |  | Unrealized Loss |  |  | Fair Value |  |  | Unrealized Loss |  |  | Fair Value |  |  | Unrealized Loss |
U.S. Treasury securities |  | $ | — |  |  | $ | — |  |  | $ | 290,535 |  |  | $ | (5,671 | ) |  | $ | 290,535 |  |  | $ | (5,671 | )
Obligations of states and political subdivisions |  |  | 6,899 |  |  |  | (43 | ) |  |  | 1,395,597 |  |  |  | (115,473 | ) |  |  | 1,402,496 |  |  |  | (115,516 | )
Residential mortgage-backed securities |  |  | 124,439 |  |  |  | (335 | ) |  |  | 2,205,425 |  |  |  | (289,695 | ) |  |  | 2,329,864 |  |  |  | (290,030 | )
Commercial mortgage-backed securities |  |  | 7,118 |  |  |  | (32 | ) |  |  | 209,632 |  |  |  | (5,763 | ) |  |  | 216,750 |  |  |  | (5,795 | )
Corporate bonds and other |  |  | — |  |  |  | — |  |  |  | 97,183 |  |  |  | (5,186 | ) |  |  | 97,183 |  |  |  | (5,186 | )
Total |  | $ | 138,456 |  |  | $ | (410 | ) |  | $ | 4,198,372 |  |  | $ | (421,788 | ) |  | $ | 4,336,828 |  |  | $ | (422,198 | )
|  | Less than 12 Months |  |  | 12 Months or Longer |  |  | Total |
December 31, 2024 |  | Fair Value |  |  | Unrealized Loss |  |  | Fair Value |  |  | Unrealized Loss |  |  | Fair Value |  |  | Unrealized Loss |
U.S. Treasury securities |  | $ | — |  |  | $ | — |  |  | $ | 271,088 |  |  | $ | (4,595 | ) |  | $ | 271,088 |  |  | $ | (4,595 | )
Obligations of states and political subdivisions |  |  | 56,777 |  |  |  | (1,224 | ) |  |  | 1,361,628 |  |  |  | (137,618 | ) |  |  | 1,418,405 |  |  |  | (138,842 | )
Residential mortgage-backed securities |  |  | 198,385 |  |  |  | (4,990 | ) |  |  | 2,048,727 |  |  |  | (373,756 | ) |  |  | 2,247,112 |  |  |  | (378,746 | )
Commercial mortgage-backed securities |  |  | 196,640 |  |  |  | (2,249 | ) |  |  | 190,189 |  |  |  | (7,409 | ) |  |  | 386,829 |  |  |  | (9,658 | )
Corporate bonds and other |  |  | 4,871 |  |  |  | (44 | ) |  |  | 95,840 |  |  |  | (6,334 | ) |  |  | 100,711 |  |  |  | (6,378 | )
Total |  | $ | 456,673 |  |  | $ | (8,507 | ) |  | $ | 3,967,472 |  |  | $ | (529,712 | ) |  | $ | 4,424,145 |  |  | $ | (538,219 | )

X
- References No definition available. + Details
Name: | us-gaap_CashAndCashEquivalentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479081/326-30-55-8 Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-6 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479106/326-30-50-4 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionFairValueTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of maturities of an entity's investments as well as any other information pertinent to the investments. + References No definition available. + Details
Name: | us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesReconciliationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration