Premises and Equipment (Summary of Leases) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Premises and Equipment
Total rent expense applicable to operating leases	$ 230	$ 215	$ 199
Rental income from owned properties and subleases	8	8	7
Operating leases, future minimum payments due, current	214
Operating leases, future minimum payments, due in two years	201
Operating leases, future minimum payments, due in three years	182
Operating leases, future minimum payments, due in four years	161
Operating leases, future minimum payments, due in five years	136
Operating leases, future minimum payments, due thereafter	$ 614