Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013
Commitments to Extend Credit
Commitments and Contingencies
Commitments outstanding	$ 299.2
Standby Letters of Credit
Commitments and Contingencies
Commitments outstanding	7.1
Commitments to Originate Mortgage Loans Held-for-Sale at Fixed Prices
Commitments and Contingencies
Commitments outstanding	42.6
Forward Sales Commitments
Commitments and Contingencies
Commitments outstanding	$ 60.9