Loans Receivable and Allowance for Loan Losses (Loans Receivable Modified as Troubled Debt Restructurings, Previous 12 Months) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012 Contracts	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	Sep. 30, 2012 Less Than 30 Days Past Due [Member] YTD [Member] Contracts
Financing Receivable, Modifications [Line Items]
Number of Contracts	7	2	0	12	4	1	0	2	2	0	0	0	0	0	0	0	0	0	0	4	1	0	0	2	0	1	0	3	1	0	0	1	0	3
Recorded Investment	$ 3,000	$ 67	$ 0	$ 4,550	$ 8,541	$ 2	$ 0	$ 177	$ 8,135	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 2,575	$ 219	$ 0	$ 0	$ 1,011	$ 0	$ 65	$ 0	$ 609	$ 187	$ 0	$ 0	$ 178	$ 0	$ 2,400
TDR contracts in payment default, period	30 days