Loans, Impaired Financing Receivable (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	$ 52,977		$ 57,374
Unpaid Contractual Principal Balance With An Allowance Recorded	24,057		26,317
Unpaid Contractual Principal Balance, Total	77,034		83,691
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	44,699	57,321	46,270
Impaired Balance With An Allowance Recorded	20,893	18,467	23,002
Impaired Balance, Total	65,592	75,788	69,272
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	4,214	7,227	5,751
Related Allowance, Total	4,214	7,227	5,751
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	46,676	44,889	45,234
Average Recorded Investment With An Allowance Recorded	20,878	20,585	21,188
Average Recorded Investment, Total	67,554	65,474	66,422
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	793	810	1,171
Interest Income Recognized With An Allowance Recorded	264	279	291
Interest Income Recognized, Total	1,057	1,089	1,462
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	837	931	1,203
Interest Income Collected With An Allowance Recorded	262	317	375
Interest Income Collected, Total	1,099	1,248	1,578
Commercial [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	85		1,743
Unpaid Contractual Principal Balance With An Allowance Recorded	1,677		775
Unpaid Contractual Principal Balance, Total	1,762		2,518
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	34	1,643	1,580
Impaired Balance With An Allowance Recorded	1,677	59	776
Impaired Balance, Total	1,711	1,702	2,356
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	514	39	308
Related Allowance, Total	514	39	308
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	1,056	735	947
Average Recorded Investment With An Allowance Recorded	759	27	214
Average Recorded Investment, Total	1,815	762	1,161
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	4	39	60
Interest Income Recognized With An Allowance Recorded	69	3	15
Interest Income Recognized, Total	73	42	75
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	2	46	65
Interest Income Collected With An Allowance Recorded	64	3	19
Interest Income Collected, Total	66	49	84
Agricultural [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	109		86
Unpaid Contractual Principal Balance, Total	109		86
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	109	238	86
Impaired Balance, Total	109	238	86
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance, Total	0	0	0
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	64	249	208
Average Recorded Investment, Total	64	249	208
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	8	(29)	(4)
Interest Income Recognized, Total	8	(29)	(4)
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	18	0	0
Interest Income Collected, Total	18	0	0
Commercial Construction [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	10,527		17,699
Unpaid Contractual Principal Balance With An Allowance Recorded	12,331		14,036
Unpaid Contractual Principal Balance, Total	22,858		31,735
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	8,205	19,155	12,799
Impaired Balance With An Allowance Recorded	10,610	9,998	11,489
Impaired Balance, Total	18,815	29,153	24,288
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	1,786	5,836	2,693
Related Allowance, Total	1,786	5,836	2,693
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	10,121	13,480	13,310
Average Recorded Investment With An Allowance Recorded	11,506	10,131	10,470
Average Recorded Investment, Total	21,627	23,611	23,780
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	(9)	116	116
Interest Income Recognized With An Allowance Recorded	1	12	14
Interest Income Recognized, Total	(8)	128	130
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	1	150	144
Interest Income Collected With An Allowance Recorded	4	53	61
Interest Income Collected, Total	5	203	205
Commercial [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	35,399		34,686
Unpaid Contractual Principal Balance With An Allowance Recorded	4,789		6,430
Unpaid Contractual Principal Balance, Total	40,188		41,116
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	30,152	31,854	29,385
Impaired Balance With An Allowance Recorded	4,059	3,054	6,430
Impaired Balance, Total	34,211	34,908	35,815
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	864	824	2,061
Related Allowance, Total	864	824	2,061
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	30,141	26,242	27,027
Average Recorded Investment With An Allowance Recorded	4,282	6,599	6,557
Average Recorded Investment, Total	34,423	32,841	33,584
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	670	599	833
Interest Income Recognized With An Allowance Recorded	115	66	182
Interest Income Recognized, Total	785	665	1,015
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	667	615	834
Interest Income Collected With An Allowance Recorded	116	79	197
Interest Income Collected, Total	783	694	1,031
Residential [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	4,291		2,601
Unpaid Contractual Principal Balance With An Allowance Recorded	5,260		4,772
Unpaid Contractual Principal Balance, Total	9,551		7,373
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	3,694	3,737	1,934
Impaired Balance With An Allowance Recorded	4,547	5,345	4,042
Impaired Balance, Total	8,241	9,082	5,976
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	1,050	523	675
Related Allowance, Total	1,050	523	675
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	2,751	3,590	3,176
Average Recorded Investment With An Allowance Recorded	4,244	3,798	3,859
Average Recorded Investment, Total	6,995	7,388	7,035
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	84	30	88
Interest Income Recognized With An Allowance Recorded	79	197	97
Interest Income Recognized, Total	163	227	185
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	99	46	80
Interest Income Collected With An Allowance Recorded	78	181	97
Interest Income Collected, Total	177	227	177
Farmland [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	2,340		278
Unpaid Contractual Principal Balance With An Allowance Recorded	0		299
Unpaid Contractual Principal Balance, Total	2,340		577
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	2,297	487	227
Impaired Balance With An Allowance Recorded	0		260
Impaired Balance, Total	2,297	487	487
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	0		12
Related Allowance, Total	0	0	12
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	2,297	381	342
Average Recorded Investment With An Allowance Recorded	87		65
Average Recorded Investment, Total	2,384	381	407
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	31	48	66
Interest Income Recognized With An Allowance Recorded	0		(18)
Interest Income Recognized, Total	31	48	48
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	44	66	66
Interest Income Collected With An Allowance Recorded	0		0
Interest Income Collected, Total	44	66	66
Consumer [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	226		229
Unpaid Contractual Principal Balance With An Allowance Recorded	0		5
Unpaid Contractual Principal Balance, Total	226		234
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	208	159	216
Impaired Balance With An Allowance Recorded	0	11	5
Impaired Balance, Total	208	170	221
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	0	5	2
Related Allowance, Total	0	5	2
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	219	174	184
Average Recorded Investment With An Allowance Recorded	0	4	4
Average Recorded Investment, Total	219	178	188
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	5	5	11
Interest Income Recognized With An Allowance Recorded	0	1	1
Interest Income Recognized, Total	5	6	12
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	6	6	12
Interest Income Collected With An Allowance Recorded	0	1	1
Interest Income Collected, Total	6	7	13
Other [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	0		52
Unpaid Contractual Principal Balance With An Allowance Recorded	0		0
Unpaid Contractual Principal Balance, Total	0		52
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	0	48	43
Impaired Balance With An Allowance Recorded	0	0	0
Impaired Balance, Total	0	48	43
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	0	0	0
Related Allowance, Total	0	0	0
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	27	38	40
Average Recorded Investment With An Allowance Recorded	0	26	19
Average Recorded Investment, Total	27	64	59
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	0	2	1
Interest Income Recognized With An Allowance Recorded	0	0	0
Interest Income Recognized, Total	0	2	1
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	0	2	2
Interest Income Collected With An Allowance Recorded	0	0	0
Interest Income Collected, Total	$ 0	$ 2	$ 2

Impaired financing receivable with no related allowance recorded.

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Impaired financing receivable with related allowance recorded.

+ References

No definition available.

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5212-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=7512638&loc=d3e5258-111524

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Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 14A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7512638&loc=SL6953550-111524

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Amount of allowance for credit losses related to recorded investment.

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Amount of interest income, recognized on accrual basis, on financing receivables that are recognized as impaired, for which there is no related allowance for credit losses.

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Amount of interest income, recognized on cash basis, on financing receivables, for which there is no related allowance for credit losses and are recognized as impaired.

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Amount of unpaid principal balance of impaired financing receivables for which there is no related allowance for credit losses.

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Amount of interest income, recognized on accrual basis, on financing receivables, for which there is a related allowance for credit losses and are recognized as impaired.

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Amount of interest income on financing receivables, for which there is a related allowance for credit losses, recognized on a cash-basis method of accounting that the financing receivables were impaired.

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Unpaid principal balance of impaired financing receivables for which there is a related allowance for credit losses.

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