Loans, Impaired Financing Receivable (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended		12 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	$ 52,828		$ 57,374
Unpaid Contractual Principal Balance With An Allowance Recorded	28,266		26,317
Unpaid Contractual Principal Balance, Total	81,094		83,691
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	44,171	47,487	46,270
Impaired Balance With An Allowance Recorded	22,536	24,978	23,002
Impaired Balance, Total	66,707	72,465	69,272
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	4,741	4,950	5,751
Related Allowance, Total	4,741	4,950	5,751
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	47,667	38,673	45,234
Average Recorded Investment With An Allowance Recorded	20,870	21,643	21,188
Average Recorded Investment, Total	68,537	60,316	66,422
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	481	373	1,171
Interest Income Recognized With An Allowance Recorded	103	297	291
Interest Income Recognized, Total	584	670	1,462
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	460	462	1,203
Interest Income Collected With An Allowance Recorded	103	376	375
Interest Income Collected, Total	563	838	1,578
Commercial [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	1,546		1,743
Unpaid Contractual Principal Balance With An Allowance Recorded	290		775
Unpaid Contractual Principal Balance, Total	1,836		2,518
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	1,456	373	1,580
Impaired Balance With An Allowance Recorded	290	0	776
Impaired Balance, Total	1,746	373	2,356
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	300	0	308
Related Allowance, Total	300	0	308
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	1,568	282	947
Average Recorded Investment With An Allowance Recorded	300	10	214
Average Recorded Investment, Total	1,868	292	1,161
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	49	7	60
Interest Income Recognized With An Allowance Recorded	2	0	15
Interest Income Recognized, Total	51	7	75
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	40	14	65
Interest Income Collected With An Allowance Recorded	5	0	19
Interest Income Collected, Total	45	14	84
Commercial Construction [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	11,998		17,699
Unpaid Contractual Principal Balance With An Allowance Recorded	17,961		14,036
Unpaid Contractual Principal Balance, Total	29,959		31,735
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	9,694	13,485	12,799
Impaired Balance With An Allowance Recorded	12,966	12,418	11,489
Impaired Balance, Total	22,660	25,903	24,288
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	2,111	2,965	2,693
Related Allowance, Total	2,111	2,965	2,693
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	11,079	10,642	13,310
Average Recorded Investment With An Allowance Recorded	11,954	10,198	10,470
Average Recorded Investment, Total	23,033	20,840	23,780
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	(7)	41	116
Interest Income Recognized With An Allowance Recorded	0	58	14
Interest Income Recognized, Total	(7)	99	130
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	4	67	144
Interest Income Collected With An Allowance Recorded	0	101	61
Interest Income Collected, Total	4	168	205
Commercial Real Estate [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	33,857		34,686
Unpaid Contractual Principal Balance With An Allowance Recorded	5,163		6,430
Unpaid Contractual Principal Balance, Total	39,020		41,116
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	28,254	28,744	29,385
Impaired Balance With An Allowance Recorded	5,141	7,072	6,430
Impaired Balance, Total	33,395	35,816	35,815
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	1,462	1,473	2,061
Related Allowance, Total	1,462	1,473	2,061
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	30,136	23,436	27,027
Average Recorded Investment With An Allowance Recorded	4,394	8,372	6,557
Average Recorded Investment, Total	34,530	31,808	33,584
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	358	251	833
Interest Income Recognized With An Allowance Recorded	55	114	182
Interest Income Recognized, Total	413	365	1,015
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	325	261	834
Interest Income Collected With An Allowance Recorded	53	151	197
Interest Income Collected, Total	378	412	1,031
Residential Real Estate [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	2,748		2,601
Unpaid Contractual Principal Balance With An Allowance Recorded	4,852		4,772
Unpaid Contractual Principal Balance, Total	7,600		7,373
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	2,152	4,277	1,934
Impaired Balance With An Allowance Recorded	4,139	5,488	4,042
Impaired Balance, Total	6,291	9,765	5,976
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	868	512	675
Related Allowance, Total	868	512	675
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	2,280	3,517	3,176
Average Recorded Investment With An Allowance Recorded	4,092	3,024	3,859
Average Recorded Investment, Total	6,372	6,541	7,035
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	46	32	88
Interest Income Recognized With An Allowance Recorded	46	125	97
Interest Income Recognized, Total	92	157	185
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	42	49	80
Interest Income Collected With An Allowance Recorded	45	124	97
Interest Income Collected, Total	87	173	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	211	227
Impaired Balance With An Allowance Recorded	0		260
Impaired Balance, Total	2,297	211	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	328	342
Average Recorded Investment With An Allowance Recorded	130		65
Average Recorded Investment, Total	2,427	328	407
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	32	66	66
Interest Income Recognized With An Allowance Recorded	0		(18)
Interest Income Recognized, Total	32	66	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
Agricultural [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	45		86
Unpaid Contractual Principal Balance With An Allowance Recorded	0
Unpaid Contractual Principal Balance, Total	45		86
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	45	196	86
Impaired Balance With An Allowance Recorded	0
Impaired Balance, Total	45	196	86
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	0
Related Allowance, Total	0	0	0
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	42	254	208
Average Recorded Investment With An Allowance Recorded	0
Average Recorded Investment, Total	42	254	208
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	0	(28)	(4)
Interest Income Recognized With An Allowance Recorded	0
Interest Income Recognized, Total	0	(28)	(4)
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	0	0	0
Interest Income Collected With An Allowance Recorded	0
Interest Income Collected, Total	0	0	0
Consumer [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	256		229
Unpaid Contractual Principal Balance With An Allowance Recorded	0		5
Unpaid Contractual Principal Balance, Total	256		234
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	237	158	216
Impaired Balance With An Allowance Recorded	0		5
Impaired Balance, Total	237	158	221
Related Allowance [Abstract]
Impaired Financing Receivable With No Related Allowance Recorded	0	0	0
Related Allowance With An Allowance Recorded	0		2
Related Allowance, Total	0	0	2
Average Recorded Investment [Abstract]
Average Recorded Investment With No Related Allowance Recorded	225	181	184
Average Recorded Investment With An Allowance Recorded	0		4
Average Recorded Investment, Total	225	181	188
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	3	3	11
Interest Income Recognized With An Allowance Recorded	0		1
Interest Income Recognized, Total	3	3	12
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	5	4	12
Interest Income Collected With An Allowance Recorded	0		1
Interest Income Collected, Total	5	4	13
Other [Member]
Unpaid Contractual Principal Balance [Abstract]
Unpaid Contractual Principal Balance With No Related Allowance Recorded	38		52
Unpaid Contractual Principal Balance With An Allowance Recorded	0		0
Unpaid Contractual Principal Balance, Total	38		52
Impaired Balance [Abstract]
Impaired Balance With No Related Allowance Recorded	36	43	43
Impaired Balance With An Allowance Recorded	0	0	0
Impaired Balance, Total	36	43	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	40	33	40
Average Recorded Investment With An Allowance Recorded	0	39	19
Average Recorded Investment, Total	40	72	59
Interest Income Recognized [Abstract]
Interest Income Recognized With No Related Allowance Recorded	0	1	1
Interest Income Recognized With An Allowance Recorded	0	0	0
Interest Income Recognized, Total	0	1	1
Interest Income Collected [Abstract]
Interest Income Collected With No Related Allowance Recorded	0	1	2
Interest Income Collected With An Allowance Recorded	0	0	0
Interest Income Collected, Total	$ 0	$ 1	$ 2