Allowance for Loan and Lease Losses (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Allowance for loan losses [Roll Forward]
Beginning balance	$ 33,245	$ 33,171	$ 33,171
Provision charged to expense	1,559	1,160	9,450
Losses charged off	2,188	2,126	12,590
Recoveries	777	967	3,214
Ending balance	33,393	33,172	33,245
Allowance for Loan Losses Ending balance: [Abstract]
Individually evaluated for impairment	3,425	4,530	3,248
Collectively evaluated for impairment	29,968	28,642	29,997
Loans Ending balance: [Abstract]
Individually evaluated for impairment	66,454	59,966	62,498
Collectively evaluated for impairment	2,496,860	2,482,202	2,488,075
Commercial Construction [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	4,033	4,023	4,023
Provision charged to expense	(212)	42	1,009
Losses charged off	0	18	1,034
Recoveries	6	19	35
Ending balance	3,827	4,066	4,033
Allowance for Loan Losses Ending balance: [Abstract]
Individually evaluated for impairment	1,911	2,180	1,820
Collectively evaluated for impairment	1,916	1,886	2,213
Loans Ending balance: [Abstract]
Individually evaluated for impairment	11,228	10,506	9,395
Collectively evaluated for impairment	91,075	103,655	110,052
Commercial Secured by Real Estate [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	13,541	11,753	11,753
Provision charged to expense	484	1,280	3,520
Losses charged off	365	96	2,035
Recoveries	22	40	303
Ending balance	13,682	12,977	13,541
Allowance for Loan Losses Ending balance: [Abstract]
Individually evaluated for impairment	1,192	1,246	1,090
Collectively evaluated for impairment	12,490	11,731	12,451
Loans Ending balance: [Abstract]
Individually evaluated for impairment	37,923	39,694	38,113
Collectively evaluated for impairment	809,884	767,215	769,100
Commercial Other [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	5,469	5,608	5,608
Provision charged to expense	(155)	718	2,330
Losses charged off	332	612	3,233
Recoveries	169	251	764
Ending balance	5,151	5,965	5,469
Allowance for Loan Losses Ending balance: [Abstract]
Individually evaluated for impairment	322	1,104	338
Collectively evaluated for impairment	4,829	4,861	5,131
Loans Ending balance: [Abstract]
Individually evaluated for impairment	16,646	9,487	14,295
Collectively evaluated for impairment	358,763	372,459	362,053
Equipment Lease Financing [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	126	112	112
Provision charged to expense	2	(7)	14
Losses charged off	0	0	0
Recoveries	0	0	0
Ending balance	128	105	126
Allowance for Loan Losses Ending balance: [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	128	105	126
Loans Ending balance: [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	9,944	8,219	9,246
Real Estate Construction [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	376	354	354
Provision charged to expense	(4)	155	183
Losses charged off	0	171	189
Recoveries	0	6	28
Ending balance	372	344	376
Allowance for Loan Losses Ending balance: [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	372	344	376
Loans Ending balance: [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	51,978	52,558	55,041
Real Estate Mortgage [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	4,767	4,302	4,302
Provision charged to expense	334	71	1,437
Losses charged off	131	190	1,123
Recoveries	10	57	151
Ending balance	4,980	4,240	4,767
Allowance for Loan Losses Ending balance: [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	4,980	4,240	4,767
Loans Ending balance: [Abstract]
Individually evaluated for impairment	657	279	695
Collectively evaluated for impairment	695,664	648,059	696,233
Home Equity [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	563	562	562
Provision charged to expense	50	29	238
Losses charged off	47	46	248
Recoveries	5	1	11
Ending balance	571	546	563
Allowance for Loan Losses Ending balance: [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	571	546	563
Loans Ending balance: [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	79,899	83,498	82,292
Consumer Direct [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	1,102	917	917
Provision charged to expense	165	(117)	892
Losses charged off	314	146	1,245
Recoveries	145	192	538
Ending balance	1,098	846	1,102
Allowance for Loan Losses Ending balance: [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	1,098	846	1,102
Loans Ending balance: [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	119,191	121,645	122,581
Consumer Indirect [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	3,268	5,540	5,540
Provision charged to expense	895	(1,011)	(173)
Losses charged off	999	847	3,483
Recoveries	420	401	1,384
Ending balance	3,584	4,083	3,268
Allowance for Loan Losses Ending balance: [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	3,584	4,083	3,268
Loans Ending balance: [Abstract]
Individually evaluated for impairment	0	0	0
Collectively evaluated for impairment	$ 280,462	$ 324,894	$ 281,477