Mortgage Banking Activities (Details Textual) (USD $)	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Mortgage Banking Activities (Textual) [Abstract]
Mortgage loans serviced for others	$ 1,100,000,000	$ 1,100,000,000
Total services loans	1,700,000	2,100,000
Fair value of mortgage servicing rights	6,800,000	5,600,000	8,200,000
Interest rate lock commitments for the future delivery of residential mortgage loans	57,500,000	39,500,000
Forward commitments for the future delivery of residential mortgage loans	13,200,000	6,900,000
Amounts held in custodial accounts	$ 18,100,000	$ 16,400,000