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Investments (Tables) | 9 Months Ended
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Sep. 30, 2020
Gross Unrecognized Gains and Losses and Cost or Amortized Cost, Allowance for Credit Losses, Carrying Amount and Fair Value of Investments Classified as Held-to-Maturity | The gross unrecognized gains and losses on, amortized cost, allowance for credit losses, carrying amount, and fair value of, those investments classified as held-to-maturity at September 30, 2020 are summarized as follows:
|  | Amortized Cost |  |  | Allowance for Credit Losses |  |  | Carrying Amount |  |  | Gross Unrecognized Gains |  |  | Gross Unrecognized Losses |  |  | Fair Value |
|  | (in thousands) |
States and political subdivisions |  | $ | 471,913 |  |  | $ | (38 | ) |  | $ | 471,875 |  |  | $ | 30,756 |  |  | $ | (8 | ) |  | $ | 502,623 |
Corporate bonds |  |  | 70,721 |  |  |  | (242 | ) |  |  | 70,479 |  |  |  | 3,106 |  |  |  | — |  |  |  | 73,585 |
U.S. agency-based mortgage-backed securities |  |  | 8,070 |  |  |  | — |  |  |  | 8,070 |  |  |  | 644 |  |  |  | — |  |  |  | 8,714 |
U.S. Treasury securities and obligations of U.S. government agencies |  |  | 21,914 |  |  |  | — |  |  |  | 21,914 |  |  |  | 326 |  |  |  | — |  |  |  | 22,240 |
Asset-backed securities |  |  | 178 |  |  |  | (8 | ) |  |  | 170 |  |  |  | 7 |  |  |  | — |  |  |  | 177 |
Totals |  | $ | 572,796 |  |  | $ | (288 | ) |  | $ | 572,508 |  |  | $ | 34,839 |  |  | $ | (8 | ) |  | $ | 607,339 |
The gross unrealized gains and losses on, and the amortized cost and fair value of, those investments classified as held-to-maturity at December 31, 2019 are summarized as follows:
|  | Amortized Cost |  |  | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Fair Value |
|  | (in thousands) |
States and political subdivisions |  | $ | 466,270 |  |  | $ | 19,570 |  |  | $ | (193 | ) |  | $ | 485,647 |
Corporate bonds |  |  | 109,241 |  |  |  | 1,684 |  |  |  | — |  |  |  | 110,925 |
U.S. agency-based mortgage-backed securities |  |  | 10,967 |  |  |  | 544 |  |  |  | — |  |  |  | 11,511 |
U.S. Treasury securities and obligations of U.S. government agencies |  |  | 12,723 |  |  |  | 330 |  |  |  | (12 | ) |  |  | 13,041 |
Asset-backed securities |  |  | 220 |  |  |  | — |  |  |  | (1 | ) |  |  | 219 |
Totals |  | $ | 599,421 |  |  | $ | 22,128 |  |  | $ | (206 | ) |  | $ | 621,343 |
Gross Unrealized Gains and Losses and Cost or Amortized Cost, Allowance for Credit Losses and Fair Value of Investments Classified as Available-for-sale | The gross unrealized gains and losses on, and the amortized cost, allowance for credit losses, and fair value of, those investments classified as available-for-sale at September 30, 2020 are summarized as follows:
|  | Amortized Cost |  |  | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Fair Value |  |  | Allowance for Credit Losses |
|  | (in thousands) |
States and political subdivisions |  | $ | 257,169 |  |  | $ | 18,235 |  |  | $ | (33 | ) |  | $ | 275,371 |  |  | $ | — |
Corporate bonds |  |  | 91,162 |  |  |  | 5,492 |  |  |  | (25 | ) |  |  | 96,629 |  |  |  | — |
U.S. agency-based mortgage-backed securities |  |  | 23,850 |  |  |  | 460 |  |  |  | — |  |  |  | 24,310 |  |  |  | — |
U.S. Treasury securities and obligations of U.S. government agencies |  |  | 28,882 |  |  |  | 1,045 |  |  |  | — |  |  |  | 29,927 |  |  |  | — |
Totals |  | $ | 401,063 |  |  | $ | 25,232 |  |  | $ | (58 | ) |  | $ | 426,237 |  |  | $ | — |
The gross unrealized gains and losses on, and the amortized cost and fair value of, those investments classified as available-for-sale at December 31, 2019 are summarized as follows:
|  | Amortized Cost |  |  | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Fair Value |
|  | (in thousands) |
States and political subdivisions |  | $ | 225,895 |  |  | $ | 11,906 |  |  | $ | (26 | ) |  | $ | 237,775 |
Corporate bonds |  |  | 130,453 |  |  |  | 3,326 |  |  |  | (1 | ) |  |  | 133,778 |
U.S. agency-based mortgage-backed securities |  |  | 29,499 |  |  |  | 64 |  |  |  | (96 | ) |  |  | 29,467 |
U.S. Treasury securities and obligations of U.S. government agencies |  |  | 39,851 |  |  |  | 317 |  |  |  | (42 | ) |  |  | 40,126 |
Totals |  | $ | 425,698 |  |  | $ | 15,613 |  |  | $ | (165 | ) |  | $ | 441,146 |
Gross Unrealized Gains and Losses and Cost of Equity | The gross unrealized gains and losses on, and the cost of equity securities at September 30, 2020 are summarized as follows:
|  | Cost |  |  | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Fair Value |
|  | (in thousands) |
Equity securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Domestic common stock |  | $ | 34,725 |  |  | $ | 2,232 |  |  | $ | (1,135 | ) |  | $ | 35,822 |
Total equity securities |  | $ | 34,725 |  |  | $ | 2,232 |  |  | $ | (1,135 | ) |  | $ | 35,822 |
The gross unrealized gains and losses on, and the cost of equity securities at December 31, 2019 are summarized as follows:
|  | Cost |  |  | Gross Unrealized Gains |  |  | Gross Unrealized Losses |  |  | Fair Value |
|  | (in thousands) |
Equity securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Domestic common stock |  | $ | 24,457 |  |  | $ | 3,446 |  |  | $ | — |  |  | $ | 27,903 |
Total equity securities |  | $ | 24,457 |  |  | $ | 3,446 |  |  | $ | — |  |  | $ | 27,903 |
Summary of Carrying Amount and Fair Value of Investments in Fixed Maturity Securities, by Contractual Maturity | A summary of the carrying amounts and fair value of investments in fixed maturity securities, classified as held-to-maturity, by contractual maturity, is as follows:
|  | September 30, 2020 |  |  | December 31, 2019 |
|  | Carrying Amount |  |  | Fair Value |  |  | Carrying Amount |  |  | Fair Value |
|  | (in thousands) |
Maturity: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Within one year |  | $ | 63,982 |  |  | $ | 64,630 |  |  | $ | 49,967 |  |  | $ | 50,348 |
After one year through five years |  |  | 182,355 |  |  |  | 190,897 |  |  |  | 198,025 |  |  |  | 202,109 |
After five years through ten years |  |  | 94,035 |  |  |  | 99,644 |  |  |  | 110,460 |  |  |  | 113,877 |
After ten years |  |  | 223,896 |  |  |  | 243,277 |  |  |  | 229,782 |  |  |  | 243,279 |
U.S. agency-based mortgage-backed securities |  |  | 8,070 |  |  |  | 8,714 |  |  |  | 10,967 |  |  |  | 11,511 |
Asset-backed securities |  |  | 170 |  |  |  | 177 |  |  |  | 220 |  |  |  | 219 |
Totals |  | $ | 572,508 |  |  | $ | 607,339 |  |  | $ | 599,421 |  |  | $ | 621,343 |
Investment Securities Continuous Unrealized Loss Position | The following table summarizes the fair value and gross unrealized losses on securities classified as available-for-sale, aggregated by major investment category and length of time that the individual securities have been in a continuous unrealized loss position as of September 30, 2020:
|  | Less Than 12 Months |  |  | 12 Months or Greater |  |  | Total |
|  | Fair Value of Investments with Unrealized Losses |  |  | Gross Unrealized Losses |  |  | Fair Value of Investments with Unrealized Losses |  |  | Gross Unrealized Losses |  |  | Fair Value of Investments with Unrealized Losses |  |  | Gross Unrealized Losses |
|  | (in thousands) |
September 30, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Available-for-Sale |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fixed maturity securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
States and political subdivisions |  | $ | 4,329 |  |  | $ | 33 |  |  | $ | — |  |  | $ | — |  |  | $ | 4,329 |  |  | $ | 33 |
Corporate bonds |  |  | 2,511 |  |  |  | 25 |  |  |  | — |  |  |  | — |  |  |  | 2,511 |  |  |  | 25 |
Total available-for-sale securities |  | $ | 6,840 |  |  | $ | 58 |  |  | $ | — |  |  | $ | — |  |  | $ | 6,840 |  |  | $ | 58 |
The following table summarizes the fair value and gross unrealized losses on securities, aggregated by major investment category and length of time that the individual securities have been in a continuous unrealized loss position as of December 31, 2019:
|  | Less Than 12 Months |  |  | 12 Months or Greater |  |  | Total |
|  | Fair Value of Investments with Unrealized Losses |  |  | Gross Unrealized Losses |  |  | Fair Value of Investments with Unrealized Losses |  |  | Gross Unrealized Losses |  |  | Fair Value of Investments with Unrealized Losses |  |  | Gross Unrealized Losses |
|  | (in thousands) |
December 31, 2019 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Held-to-Maturity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fixed maturity securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
States and political subdivisions |  | $ | 21,074 |  |  | $ | 193 |  |  | $ | — |  |  | $ | — |  |  | $ | 21,074 |  |  | $ | 193 |
U.S. Treasury securities and obligations of U.S. government agencies |  |  | — |  |  |  | — |  |  |  | 3,243 |  |  |  | 12 |  |  |  | 3,243 |  |  |  | 12 |
Asset-backed securities |  |  | — |  |  |  | — |  |  |  | 68 |  |  |  | 1 |  |  |  | 68 |  |  |  | 1 |
Total held-to-maturity securities |  |  | 21,074 |  |  |  | 193 |  |  |  | 3,311 |  |  |  | 13 |  |  |  | 24,385 |  |  |  | 206 |
Available-for-Sale |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fixed maturity securities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
States and political subdivisions |  | $ | 4,140 |  |  | $ | 26 |  |  | $ | — |  |  | $ | — |  |  | $ | 4,140 |  |  | $ | 26 |
Corporate bonds |  |  | 6,426 |  |  |  | 1 |  |  |  | — |  |  |  | — |  |  |  | 6,426 |  |  |  | 1 |
U.S. agency-based mortgage-backed securities |  |  | 13,007 |  |  |  | 95 |  |  |  | 1,152 |  |  |  | 1 |  |  |  | 14,159 |  |  |  | 96 |
U.S. Treasury securities and obligations of U.S. government agencies |  |  | — |  |  |  | — |  |  |  | 17,068 |  |  |  | 42 |  |  |  | 17,068 |  |  |  | 42 |
Total available-for-sale securities |  |  | 23,573 |  |  |  | 122 |  |  |  | 18,220 |  |  |  | 43 |  |  |  | 41,793 |  |  |  | 165 |
Total |  | $ | 44,647 |  |  | $ | 315 |  |  | $ | 21,531 |  |  | $ | 56 |  |  | $ | 66,178 |  |  | $ | 371 |
Changes in Allowance for Credit Losses by Major Security Type of Investments Classified as Held-to-Maturity | The following table illustrates the changes in the allowance for credit losses by major security type of the investments classified as held-to-maturity for the quarter ended September 30, 2020.
|  | States and Political Subdivisions |  |  | Corporate Bonds |  |  | U.S. Agency-Based Mortgage-Backed Securities |  |  | U.S. Treasury Securities and Obligations of U.S. Government Agencies |  |  | Asset-Backed Securities |  |  | Totals |
|  | (in thousands) |
Balance at June 30, 2020 |  | $ | 49 |  |  | $ | 299 |  |  | $ | — |  |  | $ | — |  |  | $ | 9 |  |  | $ | 357 |
Provision for credit loss benefit |  |  | (11 | ) |  |  | (57 | ) |  |  | — |  |  |  | — |  |  |  | (1 | ) |  |  | (69 | )
Allowance for securities purchased with credit deterioration |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |
Securities charged off |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |
Recoveries |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |
Balance at September 30, 2020 |  | $ | 38 |  |  | $ | 242 |  |  | $ | — |  |  | $ | — |  |  | $ | 8 |  |  | $ | 288 |
The following table illustrates the changes in the allowance for credit losses by major security type of the investments classified as held-to-maturity for the nine months ended September 30, 2020.
|  | States and Political Subdivisions |  |  | Corporate Bonds |  |  | U.S. Agency-Based Mortgage-Backed Securities |  |  | U.S. Treasury Securities and Obligations of U.S. Government Agencies |  |  | Asset-Backed Securities |  |  | Totals |
|  | (in thousands) |
Balance at January 1, 2020 |  | $ | 45 |  |  | $ | 245 |  |  | $ | — |  |  | $ | — |  |  | $ | 11 |  |  | $ | 301 |
Provision for credit loss benefit |  |  | (7 | ) |  |  | (3 | ) |  |  | — |  |  |  | — |  |  |  | (3 | ) |  |  | (13 | )
Allowance for securities purchased with credit deterioration |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |
Securities charged off |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |
Recoveries |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |
Balance at September 30, 2020 |  | $ | 38 |  |  | $ | 242 |  |  | $ | — |  |  | $ | — |  |  | $ | 8 |  |  | $ | 288 |
Schedule of Amortized Cost Held-to-Maturity Securities Aggregated By Credit Quality Indicator | The table below presents the amortized cost of held-to-maturity securities aggregated by credit quality indicator as of September 30, 2020.
|  | States and Political Subdivisions |  |  | Corporate Bonds |  |  | U.S. Agency-Based Mortgage-Backed Securities |  |  | U.S. Treasury Securities and Obligations of U.S. Government Agencies |  |  | Asset-Backed Securities |  |  | Totals |
|  | Amortized cost |
|  | (in thousands) |
AAA/AA/A ratings |  | $ | 469,485 |  |  | $ | 30,085 |  |  | $ | 8,070 |  |  | $ | 21,914 |  |  | $ | 124 |  |  | $ | 529,678 |
Baa/BBB ratings |  |  | 2,428 |  |  |  | 40,636 |  |  |  | — |  |  |  | — |  |  |  | 18 |  |  |  | 43,082 |
B ratings |  |  | — |  |  |  | — |  |  |  | — |  |  |  | — |  |  |  | 36 |  |  |  | 36 |
Total |  | $ | 471,913 |  |  | $ | 70,721 |  |  | $ | 8,070 |  |  | $ | 21,914 |  |  | $ | 178 |  |  | $ | 572,796 |
Available-for-Sale Securities [Member] |
Summary of Carrying Amount and Fair Value of Investments in Fixed Maturity Securities, by Contractual Maturity | A summary of the amortized cost and fair value of investments in fixed maturity securities, classified as available-for-sale, by contractual maturity, is as follows:
|  | September 30, 2020 |  |  | December 31, 2019 |
|  | Amortized Cost |  |  | Fair Value |  |  | Amortized Cost |  |  | Fair Value |
|  | (in thousands) |
Maturity: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Within one year |  | $ | 61,469 |  |  | $ | 62,203 |  |  | $ | 27,160 |  |  | $ | 27,194 |
After one year through five years |  |  | 90,936 |  |  |  | 96,406 |  |  |  | 144,142 |  |  |  | 146,469 |
After five years through ten years |  |  | 56,622 |  |  |  | 60,484 |  |  |  | 47,175 |  |  |  | 49,419 |
After ten years |  |  | 168,186 |  |  |  | 182,834 |  |  |  | 177,722 |  |  |  | 188,597 |
U.S. agency-based mortgage-backed securities |  |  | 23,850 |  |  |  | 24,310 |  |  |  | 29,499 |  |  |  | 29,467 |
Totals |  | $ | 401,063 |  |  | $ | 426,237 |  |  | $ | 425,698 |  |  | $ | 441,146 |

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