Mortgage Banking (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Mortgage Banking [Abstract]
Gain on fair value hedge ineffectiveness, net	$ 121,000	$ 172,000	$ 1,400,000
Loss on fair value hedge ineffectiveness, net				(846,000)
Period of put back response			60 days
Mortgage servicing rights [Abstract]
Balance at beginning of period			47,341,000	43,274,000
Origination of servicing assets			10,661,000	10,410,000
Change in fair value [Abstract]
Due to market changes			7,594,000	(5,678,000)
Due to runoff			(5,216,000)	(4,426,000)
Balance at end of period	60,380,000	43,580,000	60,380,000	43,580,000
Mortgage loan servicing representation and warranty expenses			885,000	7,100,000
Reserve for mortgage loan servicing put back expenses	5,900,000		5,900,000		7,800,000
Additional Accrual for Mortgage Loan Servicing Representation And Warranty Expenses		$ 4,000,000		$ 4,000,000