Loans Receivable and Allowance for Loan Losses (Schedule of Impaired Loan Receivables) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Loans With No Related Allowance:
Recorded Investment	$ 35,082	$ 37,530
Unpaid Principal Balance	41,314	45,136
Loans With An Allowance Recorded:
Recorded Investment	24,644	19,111
Unpaid Principal Balance	24,644	19,982
Total Impaired Loans:
Recorded Investment	59,726	56,641
Unpaid Principal Balance	65,958	65,118
Related Allowance	10,868	7,120
Proceeds from Collections of Impaired Financing Receivable	2,400
Commercial and industrial [Member]
Loans With No Related Allowance:
Recorded Investment	9,577	7,426
Unpaid Principal Balance	14,109	11,746
Loans With An Allowance Recorded:
Recorded Investment	3,229	5,656
Unpaid Principal Balance	3,229	6,526
Total Impaired Loans:
Recorded Investment	12,806	13,082
Unpaid Principal Balance	17,338	18,272
Related Allowance	1,790	2,399
Commercial tax-exempt [Member]
Loans With No Related Allowance:
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Total Impaired Loans:
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Owner occupied real estate [Member]
Loans With No Related Allowance:
Recorded Investment	3,795	1,929
Unpaid Principal Balance	4,351	2,301
Loans With An Allowance Recorded:
Recorded Investment	1,390	1,451
Unpaid Principal Balance	1,390	1,451
Total Impaired Loans:
Recorded Investment	5,185	3,380
Unpaid Principal Balance	5,741	3,752
Related Allowance	1,390	1,451
Commercial construction and land development [Member]
Loans With No Related Allowance:
Recorded Investment	5,574	7,716
Unpaid Principal Balance	5,987	8,500
Loans With An Allowance Recorded:
Recorded Investment	9,372	7,833
Unpaid Principal Balance	9,372	7,833
Total Impaired Loans:
Recorded Investment	14,946	15,549
Unpaid Principal Balance	15,359	16,333
Related Allowance	4,050	2,470
Commercial real estate [Member]
Loans With No Related Allowance:
Recorded Investment	8,220	12,965
Unpaid Principal Balance	8,301	14,619
Loans With An Allowance Recorded:
Recorded Investment	7,087	4,171
Unpaid Principal Balance	7,087	4,172
Total Impaired Loans:
Recorded Investment	15,307	17,136
Unpaid Principal Balance	15,388	18,791
Related Allowance	2,638	800
Residential [Member]
Loans With No Related Allowance:
Recorded Investment	5,098	4,163
Unpaid Principal Balance	5,471	4,423
Loans With An Allowance Recorded:
Recorded Investment	3,089	0
Unpaid Principal Balance	3,089	0
Total Impaired Loans:
Recorded Investment	8,187	4,163
Unpaid Principal Balance	8,560	4,423
Related Allowance	523	0
Consumer [Member]
Loans With No Related Allowance:
Recorded Investment	2,818	3,331
Unpaid Principal Balance	3,095	3,547
Loans With An Allowance Recorded:
Recorded Investment	477	0
Unpaid Principal Balance	477	0
Total Impaired Loans:
Recorded Investment	3,295	3,331
Unpaid Principal Balance	3,572	3,547
Related Allowance	477	0
No Transition From Prior Year [Member]
Loans With No Related Allowance:
Recorded Investment	25,800
Loans With An Allowance Recorded:
Recorded Investment	16,400
Downgraded as Impaired During the Period [Member]
Loans With An Allowance Recorded:
Recorded Investment	3,800
Total Impaired Loans:
Recorded Investment	13,200
Charged Off [Member]
Total Impaired Loans:
Proceeds from Collections of Impaired Financing Receivable	2,800
Transferred to Foreclosed Real Estate [Member]
Total Impaired Loans:
Proceeds from Collections of Impaired Financing Receivable	$ 2,700