Loans and Allowance for Loan Losses (Details 14) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Loan impairment
Average Recorded Investment	$ 592	$ 634	$ 595	$ 630
Recognized Interest Income	5	9	14	15
Loan losses allowance
Transfer of loans from held for investment to held for sale			199	214
Loans receivable sold during the period			190	199
Total, excluding purchased credit impaired loans
Loan impairment
Average Recorded Investment	590	630	593	626
Recognized Interest Income	5	9	14	15
Commercial portfolio
Loan impairment
Average Recorded Investment	254	320	256	323
Recognized Interest Income	2	6	7	9
Commercial portfolio | Commercial and industrial
Loan impairment
Average Recorded Investment	219	265	219	250
Recognized Interest Income	1	5	4	8
Commercial portfolio | Commercial mortgage
Loan impairment
Average Recorded Investment	35	53	37	60
Recognized Interest Income		1	2	1
Commercial portfolio | Construction
Loan impairment
Average Recorded Investment		2		13
Recognized Interest Income	1		1
Consumer portfolio
Loan impairment
Average Recorded Investment	336	310	337	303
Recognized Interest Income	3	3	7	6
Consumer portfolio | Residential mortgage
Loan impairment
Average Recorded Investment	310	288	312	282
Recognized Interest Income	3	2	6	5
Consumer portfolio | Home equity and other consumer loans
Loan impairment
Average Recorded Investment	26	22	25	21
Recognized Interest Income		1	1	1
Purchased credit-impaired loans
Loan impairment
Average Recorded Investment	$ 2	$ 4	$ 2	$ 4