v2.4.0.8
Fair Value, Assets Recorded at Fair Value on a Nonrecurring Basis Level 3 Valuation Techniques and Significant Unobservable Inputs (Details) (USD $)
In Millions, unless otherwise specified
6 Months Ended 12 Months Ended
Jun. 30, 2013
Dec. 31, 2012
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Mortgages held for sale $ 35,402 $ 42,305
Minimum [Member] | Mortgages held for sale [Member] | Discounted cash flow [Member]
   
Fair Value Inputs [Abstract]    
Discount rate 3.60% 3.40%
Loss severity 1.30% 1.30%
Default rate 0.60% 0.60%
Prepayment rate 1.00% 1.00%
Minimum [Member] | Residential Portfolio Segment [Member] | Mortgages held for sale [Member] | Discounted cash flow [Member]
   
Fair Value Inputs [Abstract]    
Discount rate 4.30% 4.10%
Loss severity 1.90% 2.00%
Default rate 1.30% 2.90%
Prepayment rate 1.00% 1.00%
Maximum [Member] | Mortgages held for sale [Member] | Discounted cash flow [Member]
   
Fair Value Inputs [Abstract]    
Discount rate 7.70% 7.50%
Loss severity 33.10% 35.30%
Default rate 17.90% 14.80%
Prepayment rate 9.60% 11.00%
Maximum [Member] | Residential Portfolio Segment [Member] | Mortgages held for sale [Member] | Discounted cash flow [Member]
   
Fair Value Inputs [Abstract]    
Discount rate 12.20% 11.90%
Loss severity 50.50% 45.00%
Default rate 5.50% 21.20%
Prepayment rate 100.00% 100.00%
Weighted Average [Member] | Mortgages held for sale [Member] | Discounted cash flow [Member]
   
Fair Value Inputs [Abstract]    
Discount rate 5.60% 5.40%
Loss severity 23.20% 26.40%
Default rate 3.30% 5.50%
Prepayment rate 5.30% 6.20%
Weighted Average [Member] | Residential Portfolio Segment [Member] | Mortgages held for sale [Member] | Discounted cash flow [Member]
   
Fair Value Inputs [Abstract]    
Discount rate 11.30% 10.90%
Loss severity 5.10% 6.00%
Default rate 2.80% 7.90%
Prepayment rate 66.70% 66.70%
Nonrecurring [Member]
   
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Mortgages held for sale 2,540 2,554
Level 3 [Member] | Nonrecurring [Member]
   
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Mortgages held for sale 988 1,045
Total insignificant level 3 assets 115 148
Total 1,103 1,193
Level 3 [Member] | Nonrecurring [Member] | Residential Portfolio Segment [Member] | Discounted cash flow [Member]
   
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]    
Mortgages held for sale $ 988 $ 1,045