• Filing Date: 2019-03-08
  • Form Type: 10-K
  • Description: Annual report
v3.10.0.1
Investments - Summary of Securities with Gross Unrealized Loss Positions Aggregated by Investment Category (Detail) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]    
Gross Unrealized Loss, Less than Twelve Months $ (871) $ (456)
Fair Value, Less than Twelve Months 47,065 93,470
Gross Unrealized Loss, Twelve Months or Longer (1,414) (817)
Fair Value, Twelve Months or Longer 72,075 34,834
Gross Unrealized Loss, Total (2,285) (1,273)
Fair Value, Total 119,140 128,304
Fixed-Maturity Securities [Member] | U.S. Treasury and U.S. Government Agencies [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Gross Unrealized Loss, Less than Twelve Months (59) (246)
Fair Value, Less than Twelve Months 21,031 40,587
Gross Unrealized Loss, Twelve Months or Longer (147) (41)
Fair Value, Twelve Months or Longer 35,393 1,938
Gross Unrealized Loss, Total (206) (287)
Fair Value, Total 56,424 42,525
Fixed-Maturity Securities [Member] | Corporate Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Gross Unrealized Loss, Less than Twelve Months (542) (174)
Fair Value, Less than Twelve Months 19,932 40,627
Gross Unrealized Loss, Twelve Months or Longer (1,267) (730)
Fair Value, Twelve Months or Longer 36,682 30,563
Gross Unrealized Loss, Total (1,809) (904)
Fair Value, Total 56,614 71,190
Fixed-Maturity Securities [Member] | State, Municipalities, and Political Subdivisions [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Gross Unrealized Loss, Less than Twelve Months (3) (30)
Fair Value, Less than Twelve Months 715 9,775
Gross Unrealized Loss, Twelve Months or Longer 0 (45)
Fair Value, Twelve Months or Longer 0 2,297
Gross Unrealized Loss, Total (3) (75)
Fair Value, Total 715 12,072
Fixed-Maturity Securities [Member] | Exchange-Traded Debt [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Gross Unrealized Loss, Less than Twelve Months (261) (6)
Fair Value, Less than Twelve Months 5,275 2,481
Gross Unrealized Loss, Twelve Months or Longer 0 (1)
Fair Value, Twelve Months or Longer 0 36
Gross Unrealized Loss, Total (261) (7)
Fair Value, Total 5,275 $ 2,517
Fixed-Maturity Securities [Member] | Redeemable Preferred Stock [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Gross Unrealized Loss, Less than Twelve Months (6)  
Fair Value, Less than Twelve Months 112  
Gross Unrealized Loss, Total (6)  
Fair Value, Total $ 112