Loans Receivable and Allowance for Loan Losses (Schedule of Impaired Loan Receivables, Average) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Loans With No Related Allowance:
Average Recorded Investment	$ 37,405	$ 32,925	$ 36,571	$ 34,964
Interest Income Recognized	132	191	386	440
Loans With An Allowance Recorded:
Average Recorded Investment	8,918	10,575	10,116	12,296
Interest Income Recognized	0	0	0	0
Total Impaired Loans:
Average Recorded Investment	46,323	43,500	46,687	47,260
Interest Income Recognized	132	191	386	440
Commercial and industrial [Member]
Loans With No Related Allowance:
Average Recorded Investment	9,797	8,964	8,925	8,310
Interest Income Recognized	60	129	188	205
Loans With An Allowance Recorded:
Average Recorded Investment	5,751	1,990	7,554	2,526
Interest Income Recognized	0	0	0	0
Total Impaired Loans:
Average Recorded Investment	15,548	10,954	16,479	10,836
Interest Income Recognized	60	129	188	205
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	5,052	4,858	5,207	4,514
Interest Income Recognized	0	0	0	10
Loans With An Allowance Recorded:
Average Recorded Investment	3,167	1,909	2,562	1,973
Interest Income Recognized	0	0	0	0
Total Impaired Loans:
Average Recorded Investment	8,219	6,767	7,769	6,487
Interest Income Recognized	0	0	0	10
Commercial construction and land development [Member]
Loans With No Related Allowance:
Average Recorded Investment	3,749	3,357	3,734	5,243
Interest Income Recognized	9	8	22	39
Loans With An Allowance Recorded:
Average Recorded Investment	0	3,142	0	4,256
Interest Income Recognized	0	0	0	0
Total Impaired Loans:
Average Recorded Investment	3,749	6,499	3,734	9,499
Interest Income Recognized	9	8	22	39
Commercial real estate [Member]
Loans With No Related Allowance:
Average Recorded Investment	10,508	9,137	10,635	9,981
Interest Income Recognized	39	40	117	128
Total Impaired Loans:
Average Recorded Investment	10,508	9,137	10,635	9,981
Interest Income Recognized	39	40	117	128
Residential [Member]
Loans With No Related Allowance:
Average Recorded Investment	6,477	4,074	6,020	4,261
Interest Income Recognized	17	8	37	35
Loans With An Allowance Recorded:
Average Recorded Investment	0	3,069	0	3,072
Interest Income Recognized	0	0	0	0
Total Impaired Loans:
Average Recorded Investment	6,477	7,143	6,020	7,333
Interest Income Recognized	17	8	37	35
Consumer [Member]
Loans With No Related Allowance:
Average Recorded Investment	1,822	2,535	2,050	2,655
Interest Income Recognized	7	6	22	23
Loans With An Allowance Recorded:
Average Recorded Investment	0	465	0	469
Interest Income Recognized	0	0	0	0
Total Impaired Loans:
Average Recorded Investment	1,822	3,000	2,050	3,124
Interest Income Recognized	$ 7	$ 6	$ 22	$ 23