Loans Receivable and Allowance for Loan Losses (Schedule of Impaired Loan Receivables, Average) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Loans With No Related Allowance:
Average Recorded Investment	$ 40,285	$ 43,380	$ 39,633	$ 46,122
Interest Income Recognized	226	252	470	582
Loans With An Allowance Recorded:
Average Recorded Investment	19,920	18,987	19,280	17,212
Interest Income Recognized	0	0	0	0
Total Impaired Loans:
Average Recorded Investment	60,205	62,367	58,913	63,334
Interest Income Recognized	226	252	470	582
Commercial and industrial [Member]
Loans With No Related Allowance:
Average Recorded Investment	9,952	11,321	9,230	12,103
Interest Income Recognized	43	31	74	92
Loans With An Allowance Recorded:
Average Recorded Investment	5,312	4,219	5,251	3,010
Interest Income Recognized	0	0	0	0
Total Impaired Loans:
Average Recorded Investment	15,264	15,540	14,481	15,113
Interest Income Recognized	43	31	74	92
Commercial tax-exempt [Member]
Loans With No Related Allowance:
Average Recorded Investment	0	0	0	0
Interest Income Recognized	0	0	0	0
Total Impaired Loans:
Average Recorded Investment	0	0	0	0
Interest Income Recognized	0	0	0	0
Owner occupied real estate [Member]
Loans With No Related Allowance:
Average Recorded Investment	2,764	4,306	2,358	5,508
Interest Income Recognized	0	43	0	123
Loans With An Allowance Recorded:
Average Recorded Investment	1,418	1,456	1,427	1,136
Interest Income Recognized	0	0	0	0
Total Impaired Loans:
Average Recorded Investment	4,182	5,762	3,785	6,644
Interest Income Recognized	0	43	0	123
Commercial construction and land development [Member]
Loans With No Related Allowance:
Average Recorded Investment	7,806	10,680	7,915	11,161
Interest Income Recognized	45	130	90	251
Loans With An Allowance Recorded:
Average Recorded Investment	7,816	13,312	7,829	13,066
Interest Income Recognized	0	0	0	0
Total Impaired Loans:
Average Recorded Investment	15,622	23,992	15,744	24,227
Interest Income Recognized	45	130	90	251
Commercial real estate [Member]
Loans With No Related Allowance:
Average Recorded Investment	11,557	10,842	12,210	11,429
Interest Income Recognized	111	39	256	96
Loans With An Allowance Recorded:
Average Recorded Investment	4,159	0	4,165	0
Interest Income Recognized	0	0	0	0
Total Impaired Loans:
Average Recorded Investment	15,716	10,842	16,375	11,429
Interest Income Recognized	111	39	256	96
Residential [Member]
Loans With No Related Allowance:
Average Recorded Investment	4,901	3,963	4,736	3,785
Interest Income Recognized	19	7	36	18
Loans With An Allowance Recorded:
Average Recorded Investment	1,051	0	526	0
Interest Income Recognized	0	0	0	0
Total Impaired Loans:
Average Recorded Investment	5,952	3,963	5,262	3,785
Interest Income Recognized	19	7	36	18
Consumer [Member]
Loans With No Related Allowance:
Average Recorded Investment	3,305	2,268	3,184	2,136
Interest Income Recognized	8	2	14	2
Loans With An Allowance Recorded:
Average Recorded Investment	164	0	82	0
Interest Income Recognized	0	0	0	0
Total Impaired Loans:
Average Recorded Investment	3,469	2,268	3,266	2,136
Interest Income Recognized	$ 8	$ 2	$ 14	$ 2