XML 59 R48.htm IDEA: XBRL DOCUMENT v3.10.0.1
Investments - Summary of Securities with Gross Unrealized Loss Positions Aggregated by Investment Category (Detail) - USD ($)
$ in Thousands
Sep. 30, 2018
Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]    
Gross Unrealized Loss, Less than Twelve Months $ (431) $ (456)
Fair Value, Less than Twelve Months 35,376 93,470
Gross Unrealized Loss, Twelve Months or Longer (1,661) (817)
Fair Value, Twelve Months or Longer 74,072 34,834
Gross Unrealized Loss, Total (2,092) (1,273)
Fair Value, Total 109,448 128,304
Fixed-Maturity Securities [Member] | U.S. Treasury and U.S. Government Agencies [Member]    
Debt Securities, Available-for-sale [Line Items]    
Gross Unrealized Loss, Less than Twelve Months (144) (246)
Fair Value, Less than Twelve Months 19,321 40,587
Gross Unrealized Loss, Twelve Months or Longer (244) (41)
Fair Value, Twelve Months or Longer 35,921 1,938
Gross Unrealized Loss, Total (388) (287)
Fair Value, Total 55,242 42,525
Fixed-Maturity Securities [Member] | Corporate Bonds [Member]    
Debt Securities, Available-for-sale [Line Items]    
Gross Unrealized Loss, Less than Twelve Months (228) (174)
Fair Value, Less than Twelve Months 11,465 40,627
Gross Unrealized Loss, Twelve Months or Longer (1,417) (730)
Fair Value, Twelve Months or Longer 38,104 30,563
Gross Unrealized Loss, Total (1,645) (904)
Fair Value, Total 49,569 71,190
Fixed-Maturity Securities [Member] | State, Municipalities, and Political Subdivisions [Member]    
Debt Securities, Available-for-sale [Line Items]    
Gross Unrealized Loss, Less than Twelve Months (6) (30)
Fair Value, Less than Twelve Months 2,027 9,775
Gross Unrealized Loss, Twelve Months or Longer   (45)
Fair Value, Twelve Months or Longer   2,297
Gross Unrealized Loss, Total (6) (75)
Fair Value, Total 2,027 12,072
Fixed-Maturity Securities [Member] | Exchange-Traded Debt [Member]    
Debt Securities, Available-for-sale [Line Items]    
Gross Unrealized Loss, Less than Twelve Months (53) (6)
Fair Value, Less than Twelve Months 2,563 2,481
Gross Unrealized Loss, Twelve Months or Longer   (1)
Fair Value, Twelve Months or Longer 47 36
Gross Unrealized Loss, Total (53) (7)
Fair Value, Total $ 2,610 $ 2,517