Loans and Allowance for Loan Losses (Details 9) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Consumer
Credit quality of consumer loans
Loans categorized by LTV ratio	$ 30,572	$ 28,717
Percentage of total loans categorized by LTV ratio	100.00%	100.00%
Consumer | LTV ratio less than 80%
Credit quality of consumer loans
Loans categorized by LTV ratio	28,081	25,848
Percentage of total loans categorized by LTV ratio	92.00%	90.00%
Consumer | LTV ratio 80-100%
Credit quality of consumer loans
Loans categorized by LTV ratio	2,082	2,303
Percentage of total loans categorized by LTV ratio	7.00%	8.00%
Consumer | LTV ratio Greater than 100%
Credit quality of consumer loans
Loans categorized by LTV ratio	303	461
Percentage of total loans categorized by LTV ratio	1.00%	2.00%
Consumer | No LTV Available
Credit quality of consumer loans
Loans categorized by LTV ratio	106	105
Consumer portfolio
Credit quality of consumer loans
Loans categorized by LTV ratio	30,352	28,477
Consumer portfolio | LTV ratio less than 80%
Credit quality of consumer loans
Loans categorized by LTV ratio	27,931	25,696
Consumer portfolio | LTV ratio 80-100%
Credit quality of consumer loans
Loans categorized by LTV ratio	2,032	2,246
Consumer portfolio | LTV ratio Greater than 100%
Credit quality of consumer loans
Loans categorized by LTV ratio	283	430
Consumer portfolio | No LTV Available
Credit quality of consumer loans
Loans categorized by LTV ratio	106	105
Consumer portfolio | Residential mortgage
Credit quality of consumer loans
Loans categorized by LTV ratio	27,408	25,374
Consumer portfolio | Residential mortgage | LTV ratio less than 80%
Credit quality of consumer loans
Loans categorized by LTV ratio	25,486	23,209
Consumer portfolio | Residential mortgage | LTV ratio 80-100%
Credit quality of consumer loans
Loans categorized by LTV ratio	1,733	1,884
Consumer portfolio | Residential mortgage | LTV ratio Greater than 100%
Credit quality of consumer loans
Loans categorized by LTV ratio	134	228
Consumer portfolio | Residential mortgage | No LTV Available
Credit quality of consumer loans
Loans categorized by LTV ratio	55	53
Consumer portfolio | Home Equity loans
Credit quality of consumer loans
Loans categorized by LTV ratio	2,944	3,103
Consumer portfolio | Home Equity loans | LTV ratio less than 80%
Credit quality of consumer loans
Loans categorized by LTV ratio	2,445	2,487
Consumer portfolio | Home Equity loans | LTV ratio 80-100%
Credit quality of consumer loans
Loans categorized by LTV ratio	299	362
Consumer portfolio | Home Equity loans | LTV ratio Greater than 100%
Credit quality of consumer loans
Loans categorized by LTV ratio	149	202
Consumer portfolio | Home Equity loans | No LTV Available
Credit quality of consumer loans
Loans categorized by LTV ratio	51	52
Purchased credit-impaired loans | Consumer
Credit quality of consumer loans
Loans categorized by LTV ratio	220	240
Purchased credit-impaired loans | Consumer | LTV ratio less than 80%
Credit quality of consumer loans
Loans categorized by LTV ratio	150	152
Purchased credit-impaired loans | Consumer | LTV ratio 80-100%
Credit quality of consumer loans
Loans categorized by LTV ratio	50	57
Purchased credit-impaired loans | Consumer | LTV ratio Greater than 100%
Credit quality of consumer loans
Loans categorized by LTV ratio	$ 20	$ 31