XML 21 R28.htm IDEA: XBRL DOCUMENT v3.3.0.814
Investments - Summary of Amortized Cost and Fair Value of Investments in Fixed Maturity Securities, Classified as Held-to-Maturity (Detail) - USD ($)
$ in Thousands
Sep. 30, 2015
Dec. 31, 2014
Investment [Line Items]    
Within one year, Amortized Cost Basis $ 125,030  
After one year through five years, Amortized Cost Basis 281,139  
After five years through ten years, Amortized Cost Basis 123,928  
After ten years, Amortized Cost Basis 70,248  
Held-to-Maturity, Amortized Cost 660,250 $ 639,631
Within one year, Fair Value 125,807  
After one year through five years, Fair Value 289,630  
After five years through ten years, Fair Value 129,689  
After ten years, Fair Value 72,719  
Total, Fair Value 679,893 $ 664,371
U.S. Agency-Based Mortgage-Backed Securities [Member]    
Investment [Line Items]    
Held-to-maturity, Amortized Cost Basis 14,094  
Held-to-maturity, Fair Value 15,486  
Commercial Mortgage-Backed Securities [Member]    
Investment [Line Items]    
Held-to-maturity, Amortized Cost Basis 43,396  
Held-to-maturity, Fair Value 43,982  
Asset-Backed Securities [Member]    
Investment [Line Items]    
Held-to-maturity, Amortized Cost Basis 2,415  
Held-to-maturity, Fair Value $ 2,580