Summary of Significant Accounting Policies Mortgage Servicing Rights Gain Loss Fair Value Derivatives (Details) (Fair Value Hedging [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	$ (7,329)	$ 7,623	$ 1,875
Interest rate lock with customers [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	3,861	428	(836)
Forward Commitments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	(11,190)	7,195	2,729
Interest Rate Swap [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	$ 0	$ 0	$ (18)