Allowance for Loan Losses (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Originated loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded	$ 72,126	$ 86,818	$ 82,411
Unpaid principal, with no related allowance recorded	85,594	109,246	97,205
Average recorded Investment, with no related allowance recorded	77,271	82,437	84,095
Interest income Recognized, with no related allowance recorded	386	439	2,749
Recorded investment, with an allowance recorded	15,718	22,685	16,457
Unpaid principal, with an allowance recorded	21,176	26,274	20,127
Related allowance, with an allowance recorded	4,464	4,673	4,252
Average recorded Investment, with an allowance recorded	16,089	23,578	29,443
Interest income Recognized, with an allowance recorded	104	182	428
PNCI loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded	1,614	2,475	1,833
Unpaid principal, with no related allowance recorded	3,689	2,516	4,038
Average recorded Investment, with no related allowance recorded	1,725	1,238	2,474
Interest income Recognized, with no related allowance recorded	4	27	138
Recorded investment, with an allowance recorded	782	242	629
Unpaid principal, with an allowance recorded	813	246	673
Related allowance, with an allowance recorded	581	103	253
Average recorded Investment, with an allowance recorded	707	121	525
Interest income Recognized, with an allowance recorded	9	3	24
RE Mortgage [Member] | Residential [Member] | Originated loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded	4,017	7,288	3,520
Unpaid principal, with no related allowance recorded	6,192	9,377	5,349
Average recorded Investment, with no related allowance recorded	3,769	8,079	6,329
Interest income Recognized, with no related allowance recorded	7	22	71
Recorded investment, with an allowance recorded	2,025	3,040	2,867
Unpaid principal, with an allowance recorded	2,252	3,524	3,432
Related allowance, with an allowance recorded	447	559	603
Average recorded Investment, with an allowance recorded	2,446	3,399	3,890
Interest income Recognized, with an allowance recorded	15	6	67
RE Mortgage [Member] | Residential [Member] | PNCI loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded
Unpaid principal, with no related allowance recorded
Average recorded Investment, with no related allowance recorded			16
Interest income Recognized, with no related allowance recorded
Recorded investment, with an allowance recorded	197	162	199
Unpaid principal, with an allowance recorded	224	162	225
Related allowance, with an allowance recorded	32	23	28
Average recorded Investment, with an allowance recorded	198	81	213
Interest income Recognized, with an allowance recorded	1	3	9
RE Mortgage [Member] | Commercial [Member] | Originated loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded	57,206	61,224	66,031
Unpaid principal, with no related allowance recorded	62,263	72,273	70,709
Average recorded Investment, with no related allowance recorded	61,619	52,833	61,299
Interest income Recognized, with no related allowance recorded	362	375	2,513
Recorded investment, with an allowance recorded	5,816	6,521	3,258
Unpaid principal, with an allowance recorded	6,095	7,010	3,556
Related allowance, with an allowance recorded	1,296	1,043	352
Average recorded Investment, with an allowance recorded	4,537	10,714	7,841
Interest income Recognized, with an allowance recorded	47	62	129
RE Mortgage [Member] | Commercial [Member] | PNCI loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded	1,271	2,072	1,468
Unpaid principal, with no related allowance recorded	3,300	2,075	3,452
Average recorded Investment, with no related allowance recorded	1,370	1,036	2,097
Interest income Recognized, with no related allowance recorded	4	26	133
Recorded investment, with an allowance recorded	519		320
Unpaid principal, with an allowance recorded	519		331
Related allowance, with an allowance recorded	508		163
Average recorded Investment, with an allowance recorded	420		121
Interest income Recognized, with an allowance recorded	7		12
Home Equity Lines [Member] | Originated loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded	5,138	4,039	4,241
Unpaid principal, with no related allowance recorded	8,437	6,755	6,691
Average recorded Investment, with no related allowance recorded	4,690	5,053	4,311
Interest income Recognized, with no related allowance recorded	5	4	58
Recorded investment, with an allowance recorded	3,244	4,332	5,412
Unpaid principal, with an allowance recorded	4,086	5,389	7,103
Related allowance, with an allowance recorded	1,576	1,498	2,237
Average recorded Investment, with an allowance recorded	4,328	3,690	6,331
Interest income Recognized, with an allowance recorded	16	11	103
Home Equity Lines [Member] | PNCI loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded	302	326	365
Unpaid principal, with no related allowance recorded	343	363	586
Average recorded Investment, with no related allowance recorded	334	163	308
Interest income Recognized, with no related allowance recorded			5
Recorded investment, with an allowance recorded	37	80	38
Unpaid principal, with an allowance recorded	41	84	41
Related allowance, with an allowance recorded	37	80	27
Average recorded Investment, with an allowance recorded	38	40	148
Interest income Recognized, with an allowance recorded			1
Home equity loans [Member] | Originated loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded	460	188	361
Unpaid principal, with no related allowance recorded	1,110	488	781
Average recorded Investment, with no related allowance recorded	411	479	329
Interest income Recognized, with no related allowance recorded		1	1
Recorded investment, with an allowance recorded	116	361	167
Unpaid principal, with an allowance recorded	166	720	396
Related allowance, with an allowance recorded	50	59	81
Average recorded Investment, with an allowance recorded	142	188	317
Interest income Recognized, with an allowance recorded	1		16
Home equity loans [Member] | PNCI loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded
Unpaid principal, with no related allowance recorded
Average recorded Investment, with no related allowance recorded			11
Interest income Recognized, with no related allowance recorded
Recorded investment, with an allowance recorded
Unpaid principal, with an allowance recorded
Related allowance, with an allowance recorded
Average recorded Investment, with an allowance recorded
Interest income Recognized, with an allowance recorded
Auto indirect [Member] | Originated loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded	151	311	163
Unpaid principal, with no related allowance recorded	292	568	311
Average recorded Investment, with no related allowance recorded	157	467	263
Interest income Recognized, with no related allowance recorded	1	1	3
Recorded investment, with an allowance recorded	25	93	34
Unpaid principal, with an allowance recorded	32	117	51
Related allowance, with an allowance recorded	7	14	5
Average recorded Investment, with an allowance recorded	30	297	102
Interest income Recognized, with an allowance recorded			1
Auto indirect [Member] | PNCI loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded
Unpaid principal, with no related allowance recorded
Average recorded Investment, with no related allowance recorded
Interest income Recognized, with no related allowance recorded
Recorded investment, with an allowance recorded
Unpaid principal, with an allowance recorded
Related allowance, with an allowance recorded
Average recorded Investment, with an allowance recorded
Interest income Recognized, with an allowance recorded
Other Consumer [Member] | Originated loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded	23	55	19
Unpaid principal, with no related allowance recorded	40	80	40
Average recorded Investment, with no related allowance recorded	21	44	42
Interest income Recognized, with no related allowance recorded
Recorded investment, with an allowance recorded	4	45	30
Unpaid principal, with an allowance recorded	4	47	32
Related allowance, with an allowance recorded	4	17	12
Average recorded Investment, with an allowance recorded	17	46	49
Interest income Recognized, with an allowance recorded			1
Other Consumer [Member] | PNCI loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded	41	77
Unpaid principal, with no related allowance recorded	46	78
Average recorded Investment, with no related allowance recorded	21	39	31
Interest income Recognized, with no related allowance recorded		1
Recorded investment, with an allowance recorded	29		72
Unpaid principal, with an allowance recorded	29		76
Related allowance, with an allowance recorded	4		35
Average recorded Investment, with an allowance recorded	51		43
Interest income Recognized, with an allowance recorded	1		2
C&I [Member] | Originated loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded	4,240	8,453	4,238
Unpaid principal, with no related allowance recorded	5,392	9,110	4,613
Average recorded Investment, with no related allowance recorded	4,239	6,597	7,500
Interest income Recognized, with no related allowance recorded	11	33	73
Recorded investment, with an allowance recorded	1,626	833	4,324
Unpaid principal, with an allowance recorded	1,680	873	4,992
Related allowance, with an allowance recorded	823	357	840
Average recorded Investment, with an allowance recorded	2,975	704	2,800
Interest income Recognized, with an allowance recorded	19	7	100
C&I [Member] | PNCI loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded
Unpaid principal, with no related allowance recorded
Average recorded Investment, with no related allowance recorded			11
Interest income Recognized, with no related allowance recorded
Recorded investment, with an allowance recorded
Unpaid principal, with an allowance recorded
Related allowance, with an allowance recorded
Average recorded Investment, with an allowance recorded
Interest income Recognized, with an allowance recorded
Construction [Member] | Residential [Member] | Originated loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded	696	4,631	3,554
Unpaid principal, with no related allowance recorded	1,442	9,642	8,227
Average recorded Investment, with no related allowance recorded	2,125	5,315	3,505
Interest income Recognized, with no related allowance recorded			20
Recorded investment, with an allowance recorded	2,713	975	42
Unpaid principal, with an allowance recorded	6,680	2,071	42
Related allowance, with an allowance recorded	219	78	11
Average recorded Investment, with an allowance recorded	1,378	815	1,543
Interest income Recognized, with an allowance recorded	5	2	6
Construction [Member] | Residential [Member] | PNCI loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded
Unpaid principal, with no related allowance recorded
Average recorded Investment, with no related allowance recorded
Interest income Recognized, with no related allowance recorded
Recorded investment, with an allowance recorded
Unpaid principal, with an allowance recorded
Related allowance, with an allowance recorded
Average recorded Investment, with an allowance recorded
Interest income Recognized, with an allowance recorded
Construction [Member] | Commercial [Member] | Originated loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded	195	629	284
Unpaid principal, with no related allowance recorded	426	953	484
Average recorded Investment, with no related allowance recorded	240	3,570	517
Interest income Recognized, with no related allowance recorded		3	10
Recorded investment, with an allowance recorded	149	6,485	323
Unpaid principal, with an allowance recorded	181	6,523	523
Related allowance, with an allowance recorded	42	1,048	111
Average recorded Investment, with an allowance recorded	236	3,725	6,570
Interest income Recognized, with an allowance recorded	1	94	5
Construction [Member] | Commercial [Member] | PNCI loans [Member]
Impaired loans
Recorded investment, with no related allowance recorded
Unpaid principal, with no related allowance recorded
Average recorded Investment, with no related allowance recorded
Interest income Recognized, with no related allowance recorded
Recorded investment, with an allowance recorded
Unpaid principal, with an allowance recorded
Related allowance, with an allowance recorded
Average recorded Investment, with an allowance recorded
Interest income Recognized, with an allowance recorded