v2.4.0.6
Borrowings - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
1 Months Ended
Aug. 31, 2012
Aug. 30, 2012
Debt Instrument [Line Items]    
Cash consideration paid on debt exchange $ 19  
Fixed-to-floating rate trust preferred securities original face amount 300  
Junior Subordinated Notes Redeemed   202
Redemption price of Fixed-to-Floating Rate Trust Preferred Securities 207  
Percentage of redemption price to liquidation amount of each trust preferred security 100.00%  
Senior Notes Due 2014 Exchanged For Senior Notes Due 2022
   
Debt Instrument [Line Items]    
Debt instrument maturity year 2014  
Interest rate 4.95%  
Senior notes, exchange amount $ 256  
Senior Notes Due 2022
   
Debt Instrument [Line Items]    
Debt instrument maturity year 2022  
Interest rate 3.225%