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Share-Based Compensation Plans - Additional Information (Detail) - USD ($) |  | 12 Months Ended | 204 Months Ended | 240 Months Ended
--- | --- | --- | --- | ---
Oct. 21, 2022 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock options awarded |  |  | 200,000 | 140,000 | 300,000 |  |
Options forfeited |  |  | 46,666 | 446,667 | 100,000 |  |
Average strike price per share |  |  | $ 20.77 | $ 28.70 | $ 52.79 |  |
Compensation expense, options |  |  | $ 300,000 | $ (1,100,000) | $ 1,600,000 |  |
Proceed from exercise of options |  |  | $ 0 | $ 0 | $ 0 |  |
Fair value of share |  |  | $ 23.31 |  |  |  | $ 23.31
Weighted average fair value of options granted |  |  | $ 2.98 | $ 6.95 | $ 1.92 |  |
Number of Penn-Patriot book value appreciation rights granted |  |  | 0 |  | 0 |  | 0
BVAR Compensation expense |  |  |  | $ 2,300,000 | $ 0 |  |
BVAR Accrued compensation expense |  |  | $ 0 | $ 2,300,000 |  |  | $ 0
Number of Penn-Patriot book value rights granted |  |  | 179,096 | 131,438 |  |  |
Number of Penn-Patriot book value rights cliff vesting |  |  | 69,034 | 97,432 |  |  |
Penn-Patriot book value rights cliff vesting period |  |  | 3 years | 3 years |  |  |
Penn-Patriot book value rights compensation expense |  |  | $ 800,000 | $ 100,000 | $ 0 |  |
Penn-Patriot book value rights accrued compensation expense |  |  | $ 700,000 | $ 100,000 |  |  | $ 700,000
Share-based Compensation Award, Tranche 1 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Number of Penn-Patriot book value appreciation rights granted |  |  |  | 2,500,000 |  |  |
Aggregate Initial Notional Value |  |  |  | 5.00% |  |  |
Penn-Patriot book value vesting, number |  |  | 34,463 | 34,006 |  |  |
Penn-Patriot book value vesting rights, percentage |  |  |  | 50.00% |  |  |
Penn-Patriot book value vesting date |  |  | Dec. 31, 2024 | Oct. 26, 2022 |  |  |
Share-based Compensation Award, Tranche 2 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Vesting date |  |  | Apr. 18, 2025 |  |  |  |
Number of Penn-Patriot book value appreciation rights granted |  |  |  | 400,000 |  |  |
Aggregate Initial Notional Value |  |  |  | 0.80% |  |  |
Penn-Patriot book value vesting, number |  |  | 20,855 |  |  |  |
Penn-Patriot book value vesting rights, percentage |  |  | 50.00% | 50.00% |  |  |
Penn-Patriots Affiliates reduction of Insured Value of specified book of premium percentage |  |  |  | 95.00% |  |  |
Penn-Patriots Affiliates reduction of Insured Value of specified book vesting date |  |  |  | Oct. 26, 2023 |  |  |
Share-based Compensation Award, Tranche 3 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Vesting date |  |  | Apr. 18, 2027 |  |  |  |
Penn-Patriot book value vesting rights, percentage |  |  | 50.00% |  |  |  |
Share-based Compensation Award, Tranche 4 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock options, vested and expected to vest |  |  | 54,745 |  |  |  | 54,745
Vesting date |  |  | Jan. 01, 2023 |  |  |  |
Penn-Patriot book value vesting rights, percentage |  |  | 16.50% |  |  |  |
Share-based Payment Arrangement, Tranche 5 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Vesting date |  |  | Jan. 01, 2024 |  |  |  |
Penn-Patriot book value vesting rights, percentage |  |  | 16.50% |  |  |  |
Share-based Compensation Award, Tranche 6 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Vesting date |  |  | Jan. 01, 2025 |  |  |  |
Penn-Patriot book value vesting rights, percentage |  |  | 17.00% |  |  |  |
Share-based Compensation Award, Tranche 7 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Vesting date |  |  | Mar. 15, 2026 |  |  |  |
Penn-Patriot book value vesting rights, percentage |  |  | 50.00% |  |  |  |
Share-based Compensation Award, Tranche 8 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Vesting date |  |  | Mar. 15, 2026 |  |  |  |
Penn-Patriot book value vesting rights, percentage |  |  | 100.00% |  |  |  |
Chief Executive Officer |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock options awarded | 200,000 |  |  |  |  |  |
Exercisable period | 7 years |  |  |  |  |  |
Chief Executive Officer | Share-based Compensation Award, Tranche 1 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Percentage of shares vested on each anniversary of the grant date | 25.00% |  |  |  |  |  |
Vesting date | Nov. 01, 2022 |  |  |  |  |  |
Chief Executive Officer | Share-based Compensation Award, Tranche 2 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Percentage of shares vested on each anniversary of the grant date | 25.00% |  |  |  |  |  |
Vesting date | Feb. 01, 2023 |  |  |  |  |  |
Chief Executive Officer | Share-based Compensation Award, Tranche 3 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Percentage of shares vested on each anniversary of the grant date | 25.00% |  |  |  |  |  |
Vesting date | May 01, 2023 |  |  |  |  |  |
Chief Executive Officer | Share-based Compensation Award, Tranche 4 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Percentage of shares vested on each anniversary of the grant date | 25.00% |  |  |  |  |  |
Vesting date | Aug. 01, 2023 |  |  |  |  |  |
Forecast |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Compensation expense, options |  | $ 600,000 |  |  |  |  |
Performance Based Stock Options |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock options awarded |  |  | 0 | 140,000 | 0 |  |
Options forfeited |  |  | 46,666 | 146,667 | 100,000 |  |
Average strike price per share |  |  |  | $ 28.70 |  |  |
Performance Based Stock Options | Strike Price of $28.70 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Options forfeited |  |  | 46,666 | 46,667 |  |  |
Time Based Option Award |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock options awarded |  |  | 200,000 | 0 | 300,000 |  |
Options forfeited |  |  | 0 | 300,000 | 0 |  |
Average strike price per share |  |  | $ 20.77 |  | $ 52.79 |  |
Restricted Stock |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Compensation expense, restricted stock |  |  | $ 2,000,000.0 | $ 2,500,000 | $ 3,200,000 |  |
Unrecognized compensation expense for non-vested restricted stock |  |  | $ 0 |  |  |  | $ 0
Restricted Stock Awards |  |  | 97,260 | 83,199 | 108,521 | 1,810,656 | 2,099,636
Weighted average fair value per share |  |  | $ 25.08 | $ 27.24 | $ 24.86 |  |
Shares vested |  |  | 100,975 | 101,048 | 128,623 |  |
Restricted Stock | Key Employees |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Restricted Stock Awards |  |  | 0 | 0 | 0 | 1,171,576 | 1,171,576
Restricted Stock | Non Employee Director |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Restricted Stock Awards |  |  | 97,260 | 83,199 | 108,521 |  |
Weighted average fair value per share |  |  | $ 25.08 | $ 27.24 | $ 24.86 |  |
Shares deferred for vesting |  |  | 32,540 | 20,392 | 30,172 |  |
Restricted Stock Units |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Compensation expense, restricted stock |  |  | $ 1,500,000 | $ 900,000 | $ 3,200,000 |  |
Unrecognized compensation expense for non-vested restricted stock |  |  | $ 700,000 |  |  |  | $ 700,000
Weighted average life of non-vested restricted stock unit |  |  | 1 year 2 months 12 days |  |  |  |
Restricted Stock Awards |  |  | 0 | 0 | 202,905 | 175,498 | 378,403
Weighted average fair value per share |  |  | $ 0 | $ 0 | $ 29.02 |  |
Shares vested |  |  | 47,633 | 44,245 | 41,667 |  |
Restricted Stock Units | Key Employees |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Restricted Stock Awards |  |  | 0 | 0 | 161,238 | 175,498 | 336,736
Weighted average fair value per share |  |  |  |  | $ 30.32 |  |
Shares vested |  |  |  |  | 3,375 |  |
Vesting year |  |  |  |  | 3 years |  |
Restricted Stock Units | Key Employees | Vesting Schedule One |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock options, vested and expected to vest |  |  |  |  | 66,957 |  |
Restricted Stock Units | Key Employees | Share-based Compensation Award, Tranche 1 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Percentage of shares vested on each anniversary of the grant date |  |  |  |  | 10.00% |  |
Vesting date |  |  |  |  | Jun. 18, 2021 |  |
Restricted Stock Units | Key Employees | Share-based Compensation Award, Tranche 2 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Percentage of shares vested on each anniversary of the grant date |  |  |  |  | 20.00% |  |
Vesting date |  |  |  |  | Jun. 18, 2022 |  |
Restricted Stock Units | Key Employees | Share-based Compensation Award, Tranche 3 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Percentage of shares vested on each anniversary of the grant date |  |  |  |  | 30.00% |  |
Vesting date |  |  |  |  | Jun. 18, 2023 |  |
Restricted Stock Units | Key Employees | Vesting Schedule Two |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Stock options, vested and expected to vest |  |  |  |  | 90,906 |  |
Percentage of shares vested on each anniversary of the grant date |  |  |  |  | 100.00% |  |
Vesting date |  |  |  |  | Mar. 15, 2023 |  |
Percentage of stock award subject to vesting |  |  |  |  | 50.00% |  |
Restricted Stock Units | Key Employees | Share-based Compensation Award, Tranche 4 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Percentage of shares vested on each anniversary of the grant date |  |  |  |  | 40.00% |  |
Vesting date |  |  |  |  | Jun. 18, 2024 |  |
Restricted Stock Units | Key Employees | Share-based Payment Arrangement, Tranche 5 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Percentage of shares vested on each anniversary of the grant date |  |  |  |  | 16.50% |  |
Vesting date |  |  |  |  | Jan. 01, 2021 |  |
Restricted Stock Units | Key Employees | Share-based Compensation Award, Tranche 6 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Percentage of shares vested on each anniversary of the grant date |  |  |  |  | 16.50% |  |
Vesting date |  |  |  |  | Jan. 01, 2022 |  |
Restricted Stock Units | Key Employees | Share-based Compensation Award, Tranche 7 |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Percentage of shares vested on each anniversary of the grant date |  |  |  |  | 17.00% |  |
Vesting date |  |  |  |  | Jan. 01, 2023 |  |
Restricted Stock Units | Non Employee Director |  |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |
Restricted Stock Awards |  |  |  |  | 41,667 |  |
Weighted average fair value per share |  |  |  |  | $ 24.00 |  |

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- Definition The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(01) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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- Definition The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(03) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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- Definition Gross number of share options (or share units) granted during the period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(01) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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- Definition Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e)(1) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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- Definition Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(01) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
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