Fair Value Measurement (Details Textual) (USD $)	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
MSR Net Carrying Amount	$ 17,213,000	$ 17,600,000	$ 16,792,000
True-up Liabitlity Discount Rate	2.99%		3.81%
True-up Liability Effect of Change in Discount Rate Increase By One Percent	900,000
True-up Liability Effect of Change in Discount Rate Decrease by One Percent	1,000,000
George Washington [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated fair value of true up liability	5,000,000	4,300,000	4,600,000
Midwest [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated fair value of true up liability	$ 7,700,000	$ 7,200,000	$ 7,300,000