Fair Value Measurement (Narrative) (Details Textual) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2011	Jul. 15, 2020 Midwest [Member]	Jun. 30, 2013 Midwest [Member]	Dec. 31, 2012 Midwest [Member]	Jun. 30, 2012 Midwest [Member]	Apr. 14, 2020 George Washington [Member]	Jun. 30, 2013 George Washington [Member]	Dec. 31, 2012 George Washington [Member]	Jun. 30, 2012 George Washington [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Mortgage Servicing Rights	$ 22,604,000	$ 21,273,000	$ 22,604,000	$ 21,273,000	$ 21,316,000	$ 21,378,000	$ 20,946,000	$ 21,179,000
Mortgage Servicing rights Valuation Allowance	482,000	3,488,000	482,000	3,488,000	2,564,000	1,234,000	2,193,000	3,539,000
Mortgage Servicing Rights Net Carrying balance	22,122,000	17,785,000	22,122,000	17,785,000	18,752,000
Mortgage Servicing Rights (MSR) Impairment (Recovery)	752,000	(1,295,000)	2,082,000	51,000	1,000,000
Impaired Collateral Dependant Loans, Recorded Investment	58,100,000	82,200,000	58,100,000	82,200,000	57,800,000
Determination Of Specific Allowance For Loan Losses	5,500,000	9,100,000	5,500,000	9,100,000	3,300,000
Collateral Dependant Impaired and Non Accrual Loans Carrying Amount	52,600,000	73,100,000	52,600,000	73,100,000	54,500,000
Impairment of Real Estate	300,000			400,000	2,200,000
Impairment of Covered Other Real Esate Owned	600,000			700,000	1,700,000
Percent of available for sale securities classified as level 2	93.00%		93.00%
Percent of available for sale securites at level 3	7.00%		7.00%
True-up Liabitlity Discount Rate	3.59%	3.41%	3.59%	3.41%
True-up Liability Effect of Change in Discount Rate Increase By One Percent	700,000		700,000
True-up Liability Effect of Change in Discount Rate Decrease by One Percent	800,000		800,000
Percent of FDIC Intrinsic Loss Estimate									20.00%
Intrinsic Loss Estimate of the FDIC									152,000,000
Percent of Asset Premium Paid									25.00%
Asset Premium Paid									20,000,000
Percent of cumulative shared loss payments under loss sharing agreements									25.00%				25.00%
Estimated fair value of true up liability										6,800,000	7,600,000	6,900,000		4,100,000	4,600,000	4,900,000
Percent of excess threshold paid by the Bank under loss sharing agreements													50.00%
Percent Theshold of Loss Sharing Agreements Paid by Bank													20.00%
Stated Threshold of Loss Sharing Agreements Paid by Bank													34,400,000
Percent of Asset Discount Under Loss Sharing Percent of Asset Discount Under Loss Sharing Agreements													25.00%
Asset discount received													$ 47,000,000
Number of loans that were 90 days or more past due, or were any on nonaccrual status			0