Loans Receivable and Allowance for Loan Losses (Schedule of Impaired Loan Receivables) (Details) (USD $)	6 Months Ended
	Jun. 30, 2012 Impaired_Loans	Dec. 31, 2011
Loans With No Related Allowance:
Recorded Investment	$ 41,341,000	$ 49,999,000
Unpaid Principal Balance	55,697,000	66,560,000
Loans With An Allowance Recorded:
Recorded Investment	23,101,000	13,505,000
Unpaid Principal Balance	24,128,000	13,672,000
Total Impaired Loans:
Recorded Investment	64,442,000	63,504,000
Unpaid Principal Balance	79,825,000	80,232,000
Related Allowance	8,320,000	3,630,000
Number of Impaired Loans	9	4
Commercial and industrial [Member]
Financing Receivable, Impaired [Line Items]
Increase (Decrease) in Impaired Financing Receivable With Related Allowance Recorded Investment	7,300,000
Loans With No Related Allowance:
Recorded Investment	10,705,000	14,504,000
Unpaid Principal Balance	16,381,000	19,672,000
Loans With An Allowance Recorded:
Recorded Investment	8,291,000	1,000,000
Unpaid Principal Balance	9,318,000	1,000,000
Total Impaired Loans:
Recorded Investment	18,996,000	15,504,000
Unpaid Principal Balance	25,699,000	20,672,000
Related Allowance	3,187,000	1,000,000
Number of Impaired Loans	2
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	3,732,000	7,000,000
Unpaid Principal Balance	4,116,000	8,845,000
Loans With An Allowance Recorded:
Recorded Investment	1,456,000	492,000
Unpaid Principal Balance	1,456,000	659,000
Total Impaired Loans:
Recorded Investment	5,188,000	7,492,000
Unpaid Principal Balance	5,572,000	9,504,000
Related Allowance	1,456,000	30,000
Commercial construction and land development [Member]
Loans With No Related Allowance:
Recorded Investment	10,154,000	11,203,000
Unpaid Principal Balance	17,762,000	19,756,000
Loans With An Allowance Recorded:
Recorded Investment	13,354,000	12,013,000
Unpaid Principal Balance	13,354,000	12,013,000
Total Impaired Loans:
Recorded Investment	23,508,000	23,216,000
Unpaid Principal Balance	31,116,000	31,769,000
Related Allowance	3,677,000	2,600,000
Commercial real estate [Member]
Loans With No Related Allowance:
Recorded Investment	10,312,000	12,117,000
Unpaid Principal Balance	10,536,000	12,390,000
Total Impaired Loans:
Recorded Investment	10,312,000	12,117,000
Unpaid Principal Balance	10,536,000	12,390,000
Related Allowance	0	0
Residential [Member]
Loans With No Related Allowance:
Recorded Investment	4,137,000	3,346,000
Unpaid Principal Balance	4,385,000	3,729,000
Total Impaired Loans:
Recorded Investment	4,137,000	3,346,000
Unpaid Principal Balance	4,385,000	3,729,000
Related Allowance	0	0
Consumer [Member]
Loans With No Related Allowance:
Recorded Investment	2,301,000	1,829,000
Unpaid Principal Balance	2,517,000	2,168,000
Total Impaired Loans:
Recorded Investment	2,301,000	1,829,000
Unpaid Principal Balance	2,517,000	2,168,000
Related Allowance	$ 0	$ 0
Collateral Dependent [Member] | Commercial and industrial [Member]
Total Impaired Loans:
Number of Impaired Loans	1
Loan collateral dependency, percent	100.00%