XML 57 R48.htm IDEA: XBRL DOCUMENT v3.8.0.1
Investments - Contractual Maturities of Corporate Bonds, Municipal Fixed-Rate Bonds, Asset-Backed Bonds, Mortgage/Agency-Backed Bonds, U.S. Government Bonds and Foreign Government Bonds (Detail) - USD ($)
$ in Thousands
Sep. 30, 2017
Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]    
Available-for-sale-securities, Fair Value/Carrying Value $ 140,025 $ 190,723
Corporate Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Less than one year 20,232  
One to two years 11,678  
Two to three years 10,029  
Three to five years 3,280  
Available-for-sale-securities, Fair Value/Carrying Value 45,219 66,412
Municipal Fixed-Rate Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Less than one year 2,250  
One to two years 724  
Two to three years 730  
Three to five years 1,170  
Available-for-sale-securities, Fair Value/Carrying Value 4,874 11,774
Asset-Backed Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
One to two years 2,638  
Two to three years 2,235  
Three to five years 1,550  
Five to ten years 450  
More than ten years 912  
Available-for-sale-securities, Fair Value/Carrying Value 7,785 10,206
Mortgage/Agency-Backed Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Three to five years 917  
Five to ten years 1,348  
More than ten years 5,065  
Available-for-sale-securities, Fair Value/Carrying Value 7,330 13,004
U.S. Government Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Less than one year 8,903  
Two to three years 10,413  
Three to five years 1,578  
Available-for-sale-securities, Fair Value/Carrying Value 20,894 29,767
Foreign Government Bonds [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Two to three years 728  
Available-for-sale-securities, Fair Value/Carrying Value $ 728 $ 3,730