Company's Financing Receivables by Classification (Parenthetical) (Detail) (USD $)
In Thousands, unless otherwise specified
Sep. 30, 2012
Dec. 31, 2011
Agent receivables, net
   
Financing Receivable, Recorded Investment [Line Items]    
Allowance for potential future losses $ 2,209 $ 2,226
Mortgage loans, net
   
Financing Receivable, Recorded Investment [Line Items]    
Allowance for potential future losses $ 2,442 $ 2,849