• Filing Date: 2014-03-12
  • Form Type: 10-K
  • Description: Annual report
v2.4.0.8
Investments - Additional Information (Detail) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Bank
Accounts
Dec. 31, 2012
Bank
Accounts
Dec. 31, 2011
Dec. 31, 2010
Schedule of Investments [Line Items]        
Statutory deposit held in cash and cash equivalent $ 300 $ 300    
Cash and cash equivalents 293,398 230,214 100,355 54,849
Deposits representing cash and cash equivalents in percentage 82.30% 90.70%    
Number of national banks 3 2    
Number of custodial accounts 2 2    
U.S. Treasury and U.S. Government Agencies [Member]
       
Schedule of Investments [Line Items]        
Statutory deposit held in cash and cash equivalent 105      
Bank Deposits [Member]
       
Schedule of Investments [Line Items]        
Cash and cash equivalents 241,378 208,890    
Custodial Accounts [Member]
       
Schedule of Investments [Line Items]        
Cash and cash equivalents 22,252 22,957    
Real Estate Investment [Member]
       
Schedule of Investments [Line Items]        
Depreciation and amortization expenses under other investments $ 388 $ 279