Loans Receivable and Allowance for Loan Losses (Troubled Debt Restructurings on Loan Receivables) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012 Concessions	Sep. 30, 2012 QTD [Member] Contracts	Sep. 30, 2011 QTD [Member] Contracts	Sep. 30, 2012 YTD [Member] Contracts	Sep. 30, 2011 YTD [Member] Contracts	Sep. 30, 2012 Commercial and industrial [Member] QTD [Member] Contracts	Sep. 30, 2011 Commercial and industrial [Member] QTD [Member] Contracts	Sep. 30, 2012 Commercial and industrial [Member] YTD [Member] Contracts	Sep. 30, 2011 Commercial and industrial [Member] YTD [Member] Contracts	Sep. 30, 2012 Commercial tax-exempt [Member] QTD [Member] Contracts	Sep. 30, 2011 Commercial tax-exempt [Member] QTD [Member] Contracts	Sep. 30, 2012 Commercial tax-exempt [Member] YTD [Member] Contracts	Sep. 30, 2011 Commercial tax-exempt [Member] YTD [Member] Contracts	Sep. 30, 2012 Owner occupied real estate [Member] QTD [Member] Contracts	Sep. 30, 2011 Owner occupied real estate [Member] QTD [Member] Contracts	Sep. 30, 2012 Owner occupied real estate [Member] YTD [Member] Contracts	Sep. 30, 2011 Owner occupied real estate [Member] YTD [Member] Contracts	Sep. 30, 2012 Commercial construction and land development [Member] QTD [Member] Contracts	Sep. 30, 2011 Commercial construction and land development [Member] QTD [Member] Contracts	Sep. 30, 2012 Commercial construction and land development [Member] YTD [Member] Contracts	Sep. 30, 2011 Commercial construction and land development [Member] YTD [Member] Contracts	Sep. 30, 2012 Commercial real estate [Member] QTD [Member] Contracts	Sep. 30, 2011 Commercial real estate [Member] QTD [Member] Contracts	Sep. 30, 2012 Commercial real estate [Member] YTD [Member] Contracts	Sep. 30, 2011 Commercial real estate [Member] YTD [Member] Contracts	Sep. 30, 2012 Residential [Member] QTD [Member] Contracts	Sep. 30, 2011 Residential [Member] QTD [Member] Contracts	Sep. 30, 2012 Residential [Member] YTD [Member] Contracts	Sep. 30, 2011 Residential [Member] YTD [Member] Contracts	Sep. 30, 2012 Consumer [Member] QTD [Member] Contracts	Sep. 30, 2011 Consumer [Member] QTD [Member] Contracts	Sep. 30, 2012 Consumer [Member] YTD [Member] Contracts	Sep. 30, 2011 Consumer [Member] YTD [Member] Contracts
Financing Receivable, Modifications [Line Items]
Number of Contracts		6	26	17	30	1	1	2	4	0	0	0	0	0	1	0	1	1	18	6	18	1	5	2	5	1	1	3	2	2	0	4	0
Recorded Investment at Time of Restructure		$ 10,938	$ 15,340	$ 16,334	$ 27,576	$ 3,404	$ 555	$ 4,666	$ 12,597	$ 0	$ 0	$ 0	$ 0	$ 0	$ 87	$ 0	$ 87	$ 3,546	$ 11,234	$ 6,942	$ 11,234	$ 3,275	$ 3,385	$ 3,343	$ 3,385	$ 49	$ 79	$ 524	$ 273	$ 664	$ 0	$ 859	$ 0
Number of concessions for classifying loans receivable as TDR	1