Investment Securities (Other investments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Cost-method Investments [Line Items]
Federal Home Loan Bank stock	$ 6,300	$ 10,700
Federal Reserve Bank stock	3,100	1,200
Other Assets [Member]
Schedule of Cost-method Investments [Line Items]
Federal Home Loan Bank stock	6,254	10,733
Federal Reserve Bank stock	3,087	1,169
Other investments	9,342	11,904
Other Assets [Member] | Other Investments [Member]
Schedule of Cost-method Investments [Line Items]
Other investments	$ 1	$ 2