XML 38 R27.htm IDEA: XBRL DOCUMENT
v3.25.2

Investment Securities, Equity Securities with Readily Determinable Fair Values and Other Investments (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2025
Investment Securities, Equity Securities with Readily Determinable Fair Values and Other Investments |
Amortized cost and estimated fair value by type of investment security | The amortized cost and estimated fair value by type of investment security at June 30, 2025 are as follows: ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Held to Maturity | ​
​ | ​ | ​ | ​ | ​ | Gross | ​ | Gross | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Amortized | ​ | unrealized | ​ | unrealized | ​ | Estimated | ​ | Carrying | ​
​ | ​ | cost | ​ | gains | ​ | losses | ​ | fair value | ​ | value | ​
​ | ​ | (Dollars in Thousands) | ​
Other securities |  | $ | 4,400 |  | $ | — |  | $ | — |  | $ | 4,400 |  | $ | 4,400 | ​
Total investment securities | ​ | $ | 4,400 | ​ | $ | — | ​ | $ | — | ​ | $ | 4,400 | ​ | $ | 4,400 | ​
​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Available for Sale Debt Securities | ​
​ | ​ | ​ | ​ | ​ | Gross | ​ | Gross | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Amortized | ​ | unrealized | ​ | unrealized | ​ | Estimated | ​ | Carrying | ​
​ | ​ | cost | ​ | gains | ​ | losses | ​ | fair value | ​ | value(1) | ​
​ | ​ | (Dollars in Thousands) | ​
Residential mortgage-backed securities | ​ | $ | 5,245,239 | ​ | $ | 25,192 | ​ | $ | (401,353) | ​ | $ | 4,869,078 | ​ | $ | 4,869,078 | ​
Obligations of states and political subdivisions | ​ |  | 152,430 | ​ |  | 5 | ​ |  | (11,670) | ​ |  | 140,765 | ​ |  | 140,765 | ​
Total investment securities | ​ | $ | 5,397,669 | ​ | $ | 25,197 | ​ | $ | (413,023) | ​ | $ | 5,009,843 | ​ | $ | 5,009,843 | ​
(1) | Included in the carrying value of residential mortgage-backed securities are $921,929 of mortgage-backed securities issued by Ginnie Mae and $3,947,149 of mortgage-backed securities issued by Fannie Mae and Freddie Mac.
​ ​ The amortized cost and estimated fair value by type of investment security at December 31, 2024 are as follows:
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Held to Maturity | ​
​ | ​ | ​ | ​ | ​ | Gross | ​ | Gross | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Amortized | ​ | unrealized | ​ | unrealized | ​ | Estimated | ​ | Carrying | ​
​ | ​ | cost | ​ | gains | ​ | losses | ​ | fair value | ​ | value | ​
​ | ​ | (Dollars in Thousands) | ​
Other securities |  | $ | 4,400 |  | $ | — |  | $ | — |  | $ | 4,400 |  | $ | 4,400 | ​
Total investment securities | ​ | $ | 4,400 | ​ | $ | — | ​ | $ | — | ​ | $ | 4,400 | ​ | $ | 4,400 | ​
​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Available for Sale | ​
​ | ​ | ​ | ​ | ​ | Gross | ​ | Gross | ​ | Estimated | ​ | ​ | ​ | ​
​ | ​ | Amortized | ​ | unrealized | ​ | unrealized | ​ | fair | ​ | Carrying | ​
​ | ​ | cost | ​ | gains | ​ | losses | ​ | value | ​ | value(1) | ​
​ | ​ | (Dollars in Thousands) | ​
Residential mortgage-backed securities |  | $ | 5,315,488 | ​ | $ | 8,858 | ​ | $ | (489,170) |  | ​ | 4,835,176 |  | ​ | 4,835,176 | ​
Obligations of states and political subdivisions | ​ |  | 156,822 | ​ |  | 331 | ​ |  | (4,413) | ​ |  | 152,740 | ​ |  | 152,740 | ​
Total investment securities | ​ | $ | 5,472,310 | ​ | $ | 9,189 | ​ | $ | (493,583) | ​ | $ | 4,987,916 | ​ | $ | 4,987,916 | ​
(1) | Included in the carrying value of residential mortgage-backed securities are $1,001,184 of mortgage-backed securities issued by Ginnie Mae and $3,833,992 of mortgage-backed securities issued by Fannie Mae and Freddie Mac.
Amortized cost and fair value of investment securities, by contractual maturity | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Held to Maturity | ​ | Available for Sale | ​
​ | ​ | Amortized | ​ | Estimated | ​ | Amortized | ​ | Estimated | ​
​ | ​ | Cost | ​ | fair value | ​ | Cost | ​ | fair value | ​
​ | ​ | (Dollars in Thousands) | ​
Due in one year or less |  | $ | 3,200 |  | $ | 3,200 |  | $ | — |  | $ | — | ​
Due after one year through five years | ​ |  | 1,200 | ​ |  | 1,200 | ​ |  | — | ​ | ​ | — | ​
Due after five years through ten years | ​ |  | — | ​ |  | — | ​ |  | 2,240 | ​ |  | 2,238 | ​
Due after ten years | ​ |  | — | ​ |  | — | ​ |  | 150,190 | ​ |  | 138,527 | ​
Residential mortgage-backed securities | ​ |  | — | ​ |  | — | ​ |  | 5,245,239 | ​ |  | 4,869,078 | ​
Total investment securities | ​ | $ | 4,400 | ​ | $ | 4,400 | ​ | $ | 5,397,669 | ​ | $ | 5,009,843 | ​
Gross unrealized losses on debt investment securities and the related fair value | Gross unrealized losses on debt investment securities and the fair value of those related securities, aggregated by investment category and length of time that individual debt securities have been in a continuous unrealized loss position at June 30, 2025, were as follows: ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Less than 12 months | ​ | 12 months or more | ​ | Total | ​
​ | ​ | ​ | ​ | ​ | Unrealized | ​ | ​ | ​ | ​ | Unrealized | ​ | ​ | ​ | ​ | Unrealized | ​
​ | ​ | Fair Value | ​ | Losses | ​ | Fair Value | ​ | Losses | ​ | Fair Value | ​ | Losses | ​
​ | ​ | (Dollars in Thousands) | ​
Available for sale: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Residential mortgage-backed securities |  | $ | 30,149 |  | $ | (73) |  | $ | 3,177,133 |  | $ | (401,280) |  | $ | 3,207,282 |  | $ | (401,353) | ​
Obligations of states and political subdivisions | ​ |  | 39,297 | ​ |  | (2,154) | ​ |  | 89,462 | ​ |  | (9,516) | ​ |  | 128,759 | ​ |  | (11,670) | ​
​ | ​ | $ | 69,446 | ​ | $ | (2,227) | ​ | $ | 3,266,595 | ​ | $ | (410,796) | ​ | $ | 3,336,041 | ​ | $ | (413,023) | ​
​ Gross unrealized losses on debt investment securities and the fair value of those related securities, aggregated by investment category and length of time that individual debt securities have been in a continuous unrealized loss position at December 31, 2024, were as follows: ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ | ​ | Less than 12 months | ​ | 12 months or more | ​ | Total
​ | ​ | ​ | ​ | ​ | Unrealized | ​ | ​ | ​ | ​ | Unrealized | ​ | ​ | ​ | ​ | Unrealized
​ | ​ | Fair Value | ​ | Losses | ​ | Fair Value | ​ | Losses | ​ | Fair Value | ​ | Losses
​ | ​ | (Dollars in Thousands)
Available for sale: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Residential mortgage-backed securities |  | $ | 544,375 |  | $ | (4,126) |  | $ | 3,358,586 |  | $ | (485,044) |  | $ | 3,902,961 |  | $ | (489,170)
Obligations of states and political subdivisions | ​ |  | 66,450 | ​ |  | (2,389) | ​ |  | 57,551 | ​ |  | (2,024) | ​ |  | 124,001 | ​ |  | (4,413)
​ | ​ | $ | 610,825 | ​ | $ | (6,515) | ​ | $ | 3,416,137 | ​ | $ | (487,068) | ​ | $ | 4,026,962 | ​ | $ | (493,583)
Summary of unrealized and realized gains and losses recognized in net income on equity securities | ​
​ | ​ | ​ | ​ | ​
​ | ​ | Three Months Ended
​ | ​ | June 30, 2025
​ | ​ | (Dollars in Thousands)
​ | ​ | ​
​ | ​ | ​ | ​ | ​
Net gains recognized during the period on equity securities |  | $ | ​ | 22
Less: Net gains and (losses) recognized during the period on equity securities sold during the period | ​ |  | ​ | —
​ | ​ | ​ | ​ | ​
Unrealized gains recognized during the reporting period on equity securities still held at the reporting date | ​ | $ | ​ | 22
​
​ | ​ | ​ | ​ | ​
​ | ​ | Three Months Ended
​ | ​ | June 30, 2024
​ | ​ | (Dollars in Thousands)
​ | ​ | ​
​ | ​ | ​ | ​ | ​
Net losses recognized during the period on equity securities |  | $ | ​ | (23)
Less: Net gains and (losses) recognized during the period on equity securities sold during the period | ​ |  | ​ | —
​ | ​ | ​ | ​ | ​
Unrealized losses recognized during the reporting period on equity securities still held at the reporting date | ​ | $ | ​ | (23)
​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
​ | ​ | ​ | ​ | ​
​ | ​ | Six Months Ended
​ | ​ | June 30, 2025
​ | ​ | (Dollars in Thousands)
​ | ​ | ​
Net gains recognized during the period on equity securities |  | $ | ​ | 89
Less: Net gains and (losses) recognized during the period on equity securities sold during the period | ​ |  | ​ | —
​ | ​ | ​ | ​ | ​
Unrealized gains recognized during the reporting period on equity securities still held at the reporting date | ​ | $ | ​ | 89
​
​ | ​ | ​ | ​ | ​
​ | ​ | Six Months Ended
​ | ​ | June 30, 2024
​ | ​ | (Dollars in Thousands)
​ | ​ | ​
Net losses recognized during the period on equity securities |  | $ | ​ | (80)
Less: Net gains and (losses) recognized during the period on equity securities sold during the period | ​ |  | ​ | —
​ | ​ | ​ | ​ | ​
Unrealized losses recognized during the reporting period on equity securities still held at the reporting date | ​ | $ | ​ | (80)

X
- Definition Tabular disclosure of realized and unrealized gain (loss) on investment in security. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(9)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(7)(c)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2 + Details
Name: | us-gaap_GainLossOnInvestmentsTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of investment. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -Name Accounting Standards Codification -Publisher FASB -URI https://asc.fasb.org/320/tableOfContent Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Name Accounting Standards Codification -Topic 321 -Publisher FASB -URI https://asc.fasb.org/321/tableOfContent Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Name Accounting Standards Codification -Topic 325 -Publisher FASB -URI https://asc.fasb.org/325/tableOfContent + Details
Name: | us-gaap_InvestmentTableTextBlock
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
- References No definition available. + Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of unrealized gains and losses on investments. + References No definition available. + Details
Name: | us-gaap_UnrealizedGainLossOnInvestmentsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration