Derivative Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Interest Rate Lock Commitments
Derivative Financial Instruments Not Designated as Hedging Instruments
Notional Amount	$ 62,459	$ 117,735
Fair Value	2,334	(117)
Forward Commitments
Derivative Financial Instruments Not Designated as Hedging Instruments
Notional Amount	62,819	109,578
Fair Value	(938)	2,959
Interest Rate Swap Agreements Receive Fixed/Pay Variable Swaps
Derivative Financial Instruments Not Designated as Hedging Instruments
Notional Amount	259,218	247,816
Fair Value	35,503	25,982
Interest Rate Swap Agreements Pay Fixed/Receive Variable Swaps
Derivative Financial Instruments Not Designated as Hedging Instruments
Notional Amount	259,218	247,816
Fair Value	(35,779)	(26,197)
Foreign Exchange Contracts Buy
Derivative Financial Instruments Not Designated as Hedging Instruments
Notional Amount	27,459	35,022
Fair Value	194	220
Foreign Exchange Contracts Sell
Derivative Financial Instruments Not Designated as Hedging Instruments
Notional Amount	9,571	25,770
Fair Value	$ (61)	$ (62)