Loans Receivable and Allowance for Loan Losses (Summary of Loans, Allowances and Impairment Balances, by Class and Impairment Method) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Allowance for loan losses:
Individually evaluated for impairment	$ 10,868	$ 7,120
Collectively evaluated for impairment	16,557	18,162
Total allowance for loan losses	27,425	25,282
Loans receivable:
Loans evaluated individually	59,726	56,641
Loans evaluated collectively	1,642,950	1,472,156
Total loans receivable	1,702,676	1,528,797
Period used to analyze future loan losses	2 years
Commercial and industrial [Member]
Allowance for loan losses:
Individually evaluated for impairment	1,790	2,399
Collectively evaluated for impairment	7,473	7,560
Total allowance for loan losses	9,263	9,959
Loans receivable:
Loans evaluated individually	12,806	13,082
Loans evaluated collectively	422,702	363,906
Total loans receivable	435,508	376,988
Commercial tax-exempt [Member]
Allowance for loan losses:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	75	83
Total allowance for loan losses	75	83
Loans receivable:
Loans evaluated individually	0	0
Loans evaluated collectively	82,507	92,202
Total loans receivable	82,507	92,202
Owner occupied real estate [Member]
Allowance for loan losses:
Individually evaluated for impairment	1,390	1,451
Collectively evaluated for impairment	787	678
Total allowance for loan losses	2,177	2,129
Loans receivable:
Loans evaluated individually	5,185	3,380
Loans evaluated collectively	295,370	264,992
Total loans receivable	300,555	268,372
Commercial construction and land development [Member]
Allowance for loan losses:
Individually evaluated for impairment	4,050	2,470
Collectively evaluated for impairment	3,439	4,752
Total allowance for loan losses	7,489	7,222
Loans receivable:
Loans evaluated individually	14,946	15,549
Loans evaluated collectively	109,430	84,850
Total loans receivable	124,376	100,399
Commercial real estate [Member]
Allowance for loan losses:
Individually evaluated for impairment	2,638	800
Collectively evaluated for impairment	3,113	3,183
Total allowance for loan losses	5,751	3,983
Loans receivable:
Loans evaluated individually	15,307	17,136
Loans evaluated collectively	435,304	377,268
Total loans receivable	450,611	394,404
Residential [Member]
Allowance for loan losses:
Individually evaluated for impairment	523	0
Collectively evaluated for impairment	356	324
Total allowance for loan losses	879	324
Loans receivable:
Loans evaluated individually	8,187	4,163
Loans evaluated collectively	86,040	79,736
Total loans receivable	94,227	83,899
Consumer [Member]
Allowance for loan losses:
Individually evaluated for impairment	477	0
Collectively evaluated for impairment	839	793
Total allowance for loan losses	1,316	793
Loans receivable:
Loans evaluated individually	3,295	3,331
Loans evaluated collectively	211,597	209,202
Total loans receivable	214,892	212,533
Unallocated [Member]
Allowance for loan losses:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	475	789
Total allowance for loan losses	475	789
Loans receivable:
Loans evaluated individually	0	0
Loans evaluated collectively	0	0
Total loans receivable	$ 0	$ 0