Loans Receivable and Allowance for Loan Losses (Schedule of Impaired Loan Receivables) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Loans With No Related Allowance:
Recorded Investment	$ 33,125	$ 36,797
Unpaid Principal Balance	35,852	39,677
Loans With An Allowance Recorded:
Recorded Investment	12,888	9,525
Unpaid Principal Balance	12,888	9,525
Total Impaired Loans:
Recorded Investment	46,013	46,322
Unpaid Principal Balance	48,740	49,202
Related Allowance	5,720	5,643
Commercial and industrial [Member]
Loans With No Related Allowance:
Recorded Investment	7,601	8,766
Unpaid Principal Balance	8,343	9,437
Loans With An Allowance Recorded:
Recorded Investment	10,121	8,216
Unpaid Principal Balance	10,121	8,216
Total Impaired Loans:
Recorded Investment	17,722	16,982
Unpaid Principal Balance	18,464	17,653
Related Allowance	4,365	4,401
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	3,482	6,155
Unpaid Principal Balance	3,935	6,636
Loans With An Allowance Recorded:
Recorded Investment	2,767	1,309
Unpaid Principal Balance	2,767	1,309
Total Impaired Loans:
Recorded Investment	6,249	7,464
Unpaid Principal Balance	6,702	7,945
Related Allowance	1,355	1,242
Commercial construction and land development [Member]
Loans With No Related Allowance:
Recorded Investment	3,670	3,810
Unpaid Principal Balance	3,670	3,810
Total Impaired Loans:
Recorded Investment	3,670	3,810
Unpaid Principal Balance	3,670	3,810
Related Allowance	0	0
Commercial real estate [Member]
Loans With No Related Allowance:
Recorded Investment	10,504	9,976
Unpaid Principal Balance	10,567	10,097
Total Impaired Loans:
Recorded Investment	10,504	9,976
Unpaid Principal Balance	10,567	10,097
Related Allowance	0	0
Residential [Member]
Loans With No Related Allowance:
Recorded Investment	5,639	5,657
Unpaid Principal Balance	6,953	7,011
Total Impaired Loans:
Recorded Investment	5,639	5,657
Unpaid Principal Balance	6,953	7,011
Related Allowance	0	0
Consumer [Member]
Loans With No Related Allowance:
Recorded Investment	2,229	2,433
Unpaid Principal Balance	2,384	2,686
Total Impaired Loans:
Recorded Investment	2,229	2,433
Unpaid Principal Balance	2,384	2,686
Related Allowance	$ 0	$ 0

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Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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