Loan Servicing (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Transfers and Servicing of Financial Assets [Abstract]
Serviced sold mortgage loans	$ 1,400,000,000	$ 1,310,000,000	$ 1,300,000,000
Serviced sold mortgage loans with recourse	14,600,000		22,600,000
Mortgage Loans Sold with Recourse, Reserve	268,000
Servicing fees included in other service income	$ 900,000