Loan Servicing (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Transfers and Servicing of Financial Assets [Abstract]
Serviced sold mortgage loans	$ 1,300,000,000	$ 1,420,000,000	$ 1,300,000,000	$ 1,420,000,000	$ 1,350,000,000
Serviced sold mortgage loans with recourse	20,300,000	32,200,000	20,300,000	32,200,000
Servicing fees included in other service income	$ 1,000,000	$ 1,400,000	$ 2,200,000	$ 2,800,000