XML 45 R35.htm IDEA: XBRL DOCUMENT v3.22.2.2
Investments - Changes in Allowance for Credit Losses by Major Security Type of Investments Classified as Held-to-Maturity (Detail)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2022
USD ($)
Sep. 30, 2022
USD ($)
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Balance $ 276 $ 195
Provision for credit loss expense (benefit) (21) 60
Balance 255 255
Amortized cost 514,865 514,865
AAA/AA/A Ratings [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Amortized cost 476,260 476,260
Baa/BBB Ratings [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Amortized cost 38,593 38,593
B Ratings [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Amortized cost 12 12
States and Political Subdivisions [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Balance 44 48
Provision for credit loss expense (benefit)   (4)
Balance 44 44
Amortized cost 434,938 434,938
States and Political Subdivisions [Member] | AAA/AA/A Ratings [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Amortized cost 431,963 431,963
States and Political Subdivisions [Member] | Baa/BBB Ratings [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Amortized cost 2,975 2,975
Corporate Bonds [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Balance 228 143
Provision for credit loss expense (benefit) (20) 65
Balance 208 208
Amortized cost 62,390 62,390
Corporate Bonds [Member] | AAA/AA/A Ratings [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Amortized cost 26,782 26,782
Corporate Bonds [Member] | Baa/BBB Ratings [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Amortized cost 35,608 35,608
U.S. Agency-Based Mortgage-Backed Securities [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Amortized cost 3,812 3,812
U.S. Agency-Based Mortgage-Backed Securities [Member] | AAA/AA/A Ratings [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Amortized cost 3,812 3,812
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Amortized cost 13,647 13,647
U.S. Treasury Securities and Obligations of U.S. Government Agencies [Member] | AAA/AA/A Ratings [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Amortized cost 13,647 13,647
Asset-Backed Securities [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Balance 4 4
Provision for credit loss expense (benefit) (1) (1)
Balance 3 3
Amortized cost 78 78
Asset-Backed Securities [Member] | AAA/AA/A Ratings [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Amortized cost 56 56
Asset-Backed Securities [Member] | Baa/BBB Ratings [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Amortized cost 10 10
Asset-Backed Securities [Member] | B Ratings [Member]    
Debt Securities Held To Maturity Credit Quality Indicator [Line Items]    
Amortized cost $ 12 $ 12