Business Segments (Statement of Operations and Total Assets by Reportable Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]
Net interest income	$ 22,467	$ 22,385
Noninterest income	13,166	14,232
Total income	35,633	36,617
Provision for loan losses	600	900
Depreciation and amortization	1,020	970
Other noninterest expenses related to segments	23,164	22,429
Total noninterest expense	24,184	23,399
Income before income taxes	10,849	12,318
Income tax expense	3,428	3,880
Net income	7,421	8,438
Total assets	3,051,848	3,028,690	3,071,884
Expenditures for long-lived assets	427	1,652
Commercial Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	19,511	19,628
Noninterest income	7,946	6,707
Total income	27,457	26,335
Provision for loan losses	600	900
Depreciation and amortization	638	602
Other noninterest expenses related to segments	15,136	14,766
Total noninterest expense	15,774	15,368
Income before income taxes	11,083	10,067
Income tax expense	3,843	3,451
Net income	7,240	6,616
Total assets	2,439,300	2,265,850
Expenditures for long-lived assets	370	892
Wealth Management Services [Member]
Segment Reporting Information [Line Items]
Net interest income	7	3
Noninterest income	7,474	7,185
Total income	7,481	7,188
Provision for loan losses	0	0
Depreciation and amortization	327	302
Other noninterest expenses related to segments	5,112	4,972
Total noninterest expense	5,439	5,274
Income before income taxes	2,042	1,914
Income tax expense	763	719
Net income	1,279	1,195
Total assets	51,737	51,560
Expenditures for long-lived assets	26	706
Corporate [Member]
Segment Reporting Information [Line Items]
Net interest income	2,949	2,754
Noninterest income	(2,254)	340
Total income	695	3,094
Provision for loan losses	0	0
Depreciation and amortization	55	66
Other noninterest expenses related to segments	2,916	2,691
Total noninterest expense	2,971	2,757
Income before income taxes	(2,276)	337
Income tax expense	(1,178)	(290)
Net income	(1,098)	627
Total assets	560,811	711,280
Expenditures for long-lived assets	$ 31	$ 54