v3.21.1

Debt Securities (Tables) | 3 Months Ended
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Mar. 31, 2021
Debt Securities [Abstract] |
Schedule of Debt Securities, Available-for-sale | The amortized cost and fair value of investment debt securities AFS, with gross unrealized gains and losses, were as follows:
| As of March 31, 2021
(in thousands) | Amortized Cost |  | Gross Unrealized Gains |  | Gross Unrealized Losses |  | Allowance for Credit Loss related to Debt Securities |  | Fair Value
U.S. Government agencies and corporations | $ | 335 |  |  | $ | 5 |  |  | $ | — |  |  | $ | — |  |  | $ | 340 |
State and political subdivisions | 672,120 |  |  | 9,510 |  |  | 7,707 |  |  | — |  |  | 673,923 |
Mortgage-backed securities | 78,512 |  |  | 1,237 |  |  | 744 |  |  | — |  |  | 79,005 |
Collateralized mortgage obligations | 717,112 |  |  | 4,546 |  |  | 5,677 |  |  | — |  |  | 715,981 |
Corporate debt securities | 423,348 |  |  | 7,995 |  |  | 3,698 |  |  | — |  |  | 427,645 |
Total debt securities | $ | 1,891,427 |  |  | $ | 23,293 |  |  | $ | 17,826 |  |  | $ | — |  |  | $ | 1,896,894 |
| As of December 31, 2020
(in thousands) | Amortized Cost |  | Gross Unrealized Gains |  | Gross Unrealized Losses |  | Allowance for Credit Loss related to Debt Securities |  | Fair Value
U.S. Government agencies and corporations | $ | 355 |  |  | $ | 6 |  |  | $ | — |  |  | $ | — |  |  | $ | 361 |
State and political subdivisions | 611,666 |  |  | 17,163 |  |  | 483 |  |  | — |  |  | 628,346 |
Mortgage-backed securities | 92,261 |  |  | 1,758 |  |  | 1 |  |  | — |  |  | 94,018 |
Collateralized mortgage obligations | 559,718 |  |  | 6,332 |  |  | 214 |  |  | — |  |  | 565,836 |
Corporate debt securities | 360,103 |  |  | 9,333 |  |  | 616 |  |  | — |  |  | 368,820 |
Total debt securities | $ | 1,624,103 |  |  | $ | 34,592 |  |  | $ | 1,314 |  |  | $ | — |  |  | $ | 1,657,381 |
Schedule of Temporary Impairment Losses | The following table presents debt securities AFS in an unrealized loss position for which an allowance for credit losses has not been recorded at March 31, 2021, aggregated by investment category and length of time in a continuous loss position:
|  |  | As of March 31, 2021
| Number of Securities |  | Less than 12 Months |  | 12 Months or More |  | Total
Available for Sale |  | Fair Value |  | Unrealized Losses |  | Fair Value |  | Unrealized Losses |  | Fair Value |  | Unrealized Losses
(in thousands, except number of securities) |  |  |  |  |  |  |  |  |  |  |  |  |
State and political subdivisions | 145 |  |  | $ | 274,770 |  |  | $ | 7,413 |  |  | $ | 9,468 |  |  | $ | 294 |  |  | $ | 284,238 |  |  | $ | 7,707 |
Mortgage-backed securities | 8 |  |  | 20,218 |  |  | 743 |  |  | 110 |  |  | 1 |  |  | 20,328 |  |  | 744 |
Collateralized mortgage obligations | 22 |  |  | 392,272 |  |  | 5,677 |  |  | — |  |  | — |  |  | 392,272 |  |  | 5,677 |
Corporate debt securities | 28 |  |  | 143,592 |  |  | 3,543 |  |  | 750 |  |  | 155 |  |  | 144,342 |  |  | 3,698 |
Total | 203 |  |  | $ | 830,852 |  |  | $ | 17,376 |  |  | $ | 10,328 |  |  | $ | 450 |  |  | $ | 841,180 |  |  | $ | 17,826 |
The following table presents debt securities AFS in an unrealized loss position for which an allowance for credit losses has not been recorded at December 31, 2020, aggregated by investment category and length of time in a continuous loss position:
|  |  | As of December 31, 2020
Available for Sale | Number of Securities |  | Less than 12 Months |  | 12 Months or More |  | Total
| Fair Value |  | Unrealized Losses |  | Fair Value |  | Unrealized Losses |  | Fair Value |  | Unrealized Losses
(in thousands, except number of securities) |  |  |  |  |  |  |  |  |  |  |  |  |
State and political subdivisions | 27 |  |  | $ | 31,489 |  |  | $ | 157 |  |  | $ | 4,065 |  |  | $ | 326 |  |  | $ | 35,554 |  |  | $ | 483 |
Mortgage-backed securities | 7 |  |  | 315 |  |  | 1 |  |  | — |  |  | — |  |  | 315 |  |  | 1 |
Collateralized mortgage obligations | 8 |  |  | 133,032 |  |  | 214 |  |  | — |  |  | — |  |  | 133,032 |  |  | 214 |
Corporate debt securities | 15 |  |  | 35,995 |  |  | 523 |  |  | 3,311 |  |  | 93 |  |  | 39,306 |  |  | 616 |
Total | 57 |  |  | $ | 200,831 |  |  | $ | 895 |  |  | $ | 7,376 |  |  | $ | 419 |  |  | $ | 208,207 |  |  | $ | 1,314 |
Schedule Proceeds and Realized Gains (Losses) | Proceeds and gross realized gains and losses on debt securities available for sale for the three months ended March 31, 2021 and 2020 were as follows:
| Three Months Ended |  |
(in thousands) | March 31, 2021 |  | March 31, 2020 |  |  |  |
Proceeds from sales of debt securities available for sale | $ | — |  |  | $ | 22,140 |  |  |  |  |
Gross realized gains from sales of debt securities available for sale | — |  |  | 155 |  |  |  |  |
Gross realized losses from sales of debt securities available for sale | — |  |  | (113) |  |  |  |  |
Net realized gain from sales of debt securities available for sale | $ | — |  |  | $ | 42 |  |  |  |  |
Investments Classified by Contractual Maturity Date | The contractual maturity distribution of investment debt securities at March 31, 2021, is shown below. Expected maturities of MBS and CMO may differ from contractual maturities because the mortgages underlying the securities may be called or prepaid without any penalties. Therefore, these securities are not included in the maturity categories in the following summary.
| Available For Sale
(in thousands) | Amortized Cost |  | Fair Value
Due in one year or less | $ | 35,751 |  |  | $ | 36,169 |
Due after one year through five years | 304,392 |  |  | 310,792 |
Due after five years through ten years | 418,530 |  |  | 416,063 |
Due after ten years | 337,130 |  |  | 338,884 |
| $ | 1,095,803 |  |  | $ | 1,101,908 |
Mortgage-backed securities | 78,512 |  |  | 79,005 |
Collateralized mortgage obligations | 717,112 |  |  | 715,981 |
Total | $ | 1,891,427 |  |  | $ | 1,896,894 |

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