Derivative Financial Instruments (Balance sheet category and fair values of derivative instruments (not designated as hedging instruments)) (Details) (Not Designated as Hedging Instrument, USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Interest Rate Lock Commitments
Derivatives, Fair Value [Line Items]
Notional Amount	$ 193,522	$ 267,397
Forward Contracts
Derivatives, Fair Value [Line Items]
Notional Amount	146,444	168,910
Notional Amount	227,118	351,996
Other Assets | Interest Rate Lock Commitments
Derivatives, Fair Value [Line Items]
Fair Value	6,683	9,353
Other Assets | Forward Contracts
Derivatives, Fair Value [Line Items]
Fair Value	636	462
Other Liabilities | Forward Contracts
Derivatives, Fair Value [Line Items]
Fair Value	$ (1,024)	$ (1,221)