Loan Servicing (Narrative) (Details) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Transfers and Servicing of Financial Assets [Abstract]
Serviced sold mortgage loans	$ 1,300,000,000	$ 1,300,000,000	$ 1,350,000,000	$ 1,410,000,000
Serviced sold mortgage loans with recourse	19,100,000	19,100,000		30,600,000
Servicing fees included in other service income	$ 900,000	$ 2,700,000