XML 57 R46.htm IDEA: XBRL DOCUMENT v3.20.2
Investments (Unrealized Losses) (Details)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2019
USD ($)
Jun. 30, 2019
USD ($)
Jun. 30, 2020
USD ($)
security
Mar. 31, 2020
USD ($)
Jan. 01, 2020
USD ($)
Dec. 31, 2019
USD ($)
Mar. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Available-for-Sale Securities and Held-to-Maturity Securities [Line Items]                
Debt securities, held to maturity     $ 6,903,782     $ 7,106,245    
Debt securities available for sale     3,373,113     3,356,945    
Securities, other-than-temporarily impaired $ 5,900 $ 5,900            
Valuation allowance for mortgage loans $ 675 $ 675 $ 2,227 $ 1,885 $ 1,200 675 $ 675 $ 675
Debt Securities                
Available-for-Sale Securities and Held-to-Maturity Securities [Line Items]                
Gross unrealized losses, number of issues | security     75          
Gross unrealized losses, percentage of total debt     5.40%          
Gross unrealized losses, market value as a percent of amortized cost     92.70%          
Gross unrealized losses, number of securities with maturities of 12 months or greater | security     8          
Gross unrealized losses, number of securities with maturities of 12 months or greater (as a percentage)     10.70%          
External Credit Rating, Investment Grade | Debt Securities                
Available-for-Sale Securities and Held-to-Maturity Securities [Line Items]                
Gross unrealized losses, number of securities rated investment grade | security     55          
Ozark National Life Insurance Company                
Available-for-Sale Securities and Held-to-Maturity Securities [Line Items]                
Debt securities, held to maturity     $ 329,800     307,200    
Debt securities available for sale     $ 408,300     $ 415,700