Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Loss Contingencies [Line Items]
Number of months in which the majority of loan commitments are expected to fund loans	3 months
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating leases, future minimum payments due - 2014	$ 10.9
Operating leases, future minimum payments due - 2015	10.9
Operating leases, future minimum payments due - 2016	8.1
Operating leases, future minimum payments due - 2017	5.7
Operating leases, future minimum payments due - 2018	2.5
Operating leases, future minimum payments due - 2019 and thereafter	6.9
Consumer Price Index increase	3.00%
Operating lease rent expense	11.6	10.8	10.8
Commitments to Extend Credit [Member]
Loss Contingencies [Line Items]
Face amount of off-balance sheet liability	878	740
Expiration period of commitments to extend credit	1 year
Face amount of off-balance sheet liability with expiration greater than five years	61
Commitments to Extend Credit [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Expiration period of commitments to extend credit	5 years
Standby Letters of Credit [Member]
Loss Contingencies [Line Items]
Face amount of off-balance sheet liability	47	43
Loan Origination Commitments [Member]
Loss Contingencies [Line Items]
Face amount of off-balance sheet liability	197	203
Loan Origination Commitments [Member] | Real Estate Residential Loans [Member]
Loss Contingencies [Line Items]
Face amount of off-balance sheet liability	$ 11	$ 48