Fair Value Measurements Narrative (Details) (USD $)	3 Months Ended		3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2012 Minimum [Member]	Mar. 31, 2012 Maximum [Member]	Mar. 31, 2012 Equity Securities [Member]	Dec. 31, 2011 Equity Securities [Member]	Mar. 31, 2012 Corporate Debt Securities [Member]	Dec. 31, 2011 Corporate Debt Securities [Member]	Mar. 31, 2012 Single-issuer Trust Preferred Securities [Member]	Dec. 31, 2011 Single-issuer Trust Preferred Securities [Member]	Mar. 31, 2012 Pooled Trust Preferred Securities [Member]	Dec. 31, 2011 Pooled Trust Preferred Securities [Member]	Mar. 31, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member]	Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member]	Mar. 31, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member] Equity Securities Financial Institution [Member]	Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member] Equity Securities Financial Institution [Member]	Mar. 31, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member] Equity Securities, Other [Member]	Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member] Equity Securities, Other [Member]	Dec. 31, 2010 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member] Equity Securities, Other [Member]	Mar. 31, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member] Financial Institutions Subordinated Debt [Member]	Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member] Financial Institutions Subordinated Debt [Member]	Mar. 31, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member] Single-issuer Trust Preferred Securities [Member]	Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member] Single-issuer Trust Preferred Securities [Member]	Mar. 31, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member] Other Corporate Debt [Member]	Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member] Other Corporate Debt [Member]	Mar. 31, 2012 Fair Value, Measurements, Recurring [Member] Estimate of Fair Value, Fair Value Disclosure [Member] Single-issuer Trust Preferred Securities [Member]	Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Estimate of Fair Value, Fair Value Disclosure [Member] Single-issuer Trust Preferred Securities [Member]	Mar. 31, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member] Single-issuer Trust Preferred Securities [Member]	Dec. 31, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member] Single-issuer Trust Preferred Securities [Member]	Mar. 31, 2012 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member] Pooled Trust Preferred Securities [Member]	Mar. 31, 2012 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 31, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member]
Short Term Investments Maximum Borrowing Term In Days	greater than 90 days
Significant Input, Assumed Market Return to Liquidity, Years	3 years
Fair Value, Equity Securities, Value Test Coverage, Percent	80.00%
Fair Value, Equity Securities, Fair Value Price Difference Threshold, Percent	5.00%
Short Term Borrowings, Reprice Period, In Days	90
Available-for-sale Securities, Equity Securities															$ 26,800,000	$ 27,900,000	$ 6,600,000	$ 6,700,000	$ 7,100,000
Restricted equity securities issued by the Federal Home Loan Bank and Federal Reserve Bank					79,700,000	82,500,000							79,700,000	82,500,000
Corporate debt securities	2,969,680,000						127,580,000	123,306,000	77,625,000	74,365,000	5,062,000	5,109,000								42,400,000	41,300,000	73,200,000	70,200,000	2,500,000	2,500,000	77,600,000	74,400,000	4,400,000	4,200,000	5,100,000
Other real estate owned (OREO)	33,516,000	30,803,000																													33,500,000	30,800,000
Servicing Asset at Amortized Value, Fair Value																															$ 33,700,000	$ 33,100,000
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Prepayment Speed			11.00%	18.50%