v3.22.2.2
Fair Value Measurements - Summarizes Carrying Value and Estimated Fair Values of Financial Instruments not Carried at Fair Value (Detail) - USD ($)
$ in Thousands
Sep. 30, 2022
Dec. 31, 2021
Nov. 23, 2021
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Carrying Value $ 105,882 $ 106,985  
Estimated Fair Value 104,558 106,187  
Surplus note      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Carrying Value $ 5,882 6,985  
Unsecured Debt | 5.625% Senior Unsecured Notes Due 2026      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Stated percentage 5.625%   5.625%
Surplus note | Surplus note      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Carrying Value $ 5,882 6,985  
Estimated Fair Value 5,516 6,723  
5.625% Senior unsecured notes      
Fair Value Measurement Inputs and Valuation Techniques [Line Items]      
Carrying Value 100,000 100,000  
Estimated Fair Value $ 99,042 $ 99,464