Derivative Financial Instruments Part 1 (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Designated as Hedging Instrument [Member] | Forward Contracts [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet obligations	$ 292,000,000		$ 310,300,000
Negative valuation adjustment	804,000		738,000
Not Designated as Hedging Instrument [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Net negative ineffectiveness on MSR fair value		1,000,000
Net positive ineffectiveness on MSR fair value	1,300,000
Market value of posted collateral	1,300,000
Number of risk participation agreements	2		2
Aggregate notional amount of credit risk participation agreements	10,000,000		10,100,000
Not Designated as Hedging Instrument [Member] | Interest Rate Lock Commitments Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Off-balance sheet obligations	180,600,000		186,900,000
Positive valuation adjustment	1,900,000		2,300,000
Not Designated as Hedging Instrument [Member] | Interest Rate Swap [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount of mirror-image derivative contracts	367,000,000		321,300,000
Termination value of derivatives	$ 5,000,000		$ 5,400,000