v2.4.0.8
Borrowings - Additional Information (Detail) (USD $)
0 Months Ended 9 Months Ended 0 Months Ended
Sep. 30, 2014
Dec. 31, 2013
Dec. 31, 2012
Apr. 07, 2014
5.000% Notes
Sep. 30, 2014
5.000% Notes
Apr. 07, 2014
5.000% Notes
May 29, 2014
Credit Facility
Sep. 30, 2014
Credit Facility
May 29, 2014
Credit Facility
Debt Instrument [Line Items]                  
Senior notes issued     $ 600,000,000   $ 500,000,000 $ 500,000,000      
Debt instrument, interest rate         5.00% 5.00%      
Debt instrument, maturity date       Jun. 15, 2044 Jun. 15, 2044        
Interest rate, payment terms       Interest is payable semiannually in arrears on June 15 and December 15 of each year, commencing December 15, 2014.          
Interest payment commencement date       Dec. 15, 2014          
Credit facility, maximum borrowing capacity                 1,100,000,000
Debt instrument, maturity date description             The amendment, among other things, extended the maturity date of the Credit Facility from July 13, 2017 to May 29, 2019.    
Line of credit expiration date             May 29, 2019    
Outstanding borrowings               0  
Fair value of the CLO assets $ 7,500,000,000 $ 9,500,000,000