Loans and ALLL (Credit quality indicators for commercial and agricultural credit exposures) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Credit quality indicators for commercial and agricultural credit exposures
Total	$ 796,537	$ 760,817
Commercial real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	291,860	275,620
Commercial other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	100,244	95,885
Total commercial [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	392,104	371,505
Agricultural real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	59,257	49,393
Agricultural other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	33,332	34,213
Total agricultural [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	92,589	83,606
2 - High quality [Member] | Commercial real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	18,671	25,209
2 - High quality [Member] | Commercial other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	14,461	15,536
2 - High quality [Member] | Total commercial [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	33,132	40,745
2 - High quality [Member] | Agricultural real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	3,527	2,955
2 - High quality [Member] | Agricultural other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	3,235	2,313
2 - High quality [Member] | Total agricultural [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	6,762	5,268
3 - High satisfactory [Member] | Commercial real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	91,323	83,805
3 - High satisfactory [Member] | Commercial other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	39,403	28,974
3 - High satisfactory [Member] | Total commercial [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	130,726	112,779
3 - High satisfactory [Member] | Agricultural real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	26,015	16,972
3 - High satisfactory [Member] | Agricultural other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	17,000	11,886
3 - High satisfactory [Member] | Total agricultural [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	43,015	28,858
4 - Low satisfactory [Member] | Commercial real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	149,921	127,423
4 - Low satisfactory [Member] | Commercial other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	43,809	45,143
4 - Low satisfactory [Member] | Total commercial [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	193,730	172,566
4 - Low satisfactory [Member] | Agricultural real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	26,874	27,291
4 - Low satisfactory [Member] | Agricultural other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	10,902	15,437
4 - Low satisfactory [Member] | Total agricultural [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	37,776	42,728
5 - Special mention [Member] | Commercial real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	13,747	16,046
5 - Special mention [Member] | Commercial other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	1,843	1,692
5 - Special mention [Member] | Total commercial [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	15,590	17,738
5 - Special mention [Member] | Agricultural real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	1,609	1,008
5 - Special mention [Member] | Agricultural other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	922	3,191
5 - Special mention [Member] | Total agricultural [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	2,531	4,199
6 - Substandard [Member] | Commercial real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	16,974	20,029
6 - Substandard [Member] | Commercial other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	473	2,224
6 - Substandard [Member] | Total commercial [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	17,447	22,253
6 - Substandard [Member] | Agricultural real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	1,232	1,167
6 - Substandard [Member] | Agricultural other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	1,273	1,217
6 - Substandard [Member] | Total agricultural [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	2,505	2,384
7 - Vulnerable [Member] | Commercial real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	1,041	1,512
7 - Vulnerable [Member] | Commercial other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	238	2,294
7 - Vulnerable [Member] | Total commercial [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	1,279	3,806
7 - Vulnerable [Member] | Agricultural real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	0	0
7 - Vulnerable [Member] | Agricultural other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	0	0
7 - Vulnerable [Member] | Total agricultural [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	0	0
8 - Doubtful [Member] | Commercial real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	183	1,596
8 - Doubtful [Member] | Commercial other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	17	22
8 - Doubtful [Member] | Total commercial [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	200	1,618
8 - Doubtful [Member] | Agricultural real estate [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	0	0
8 - Doubtful [Member] | Agricultural other [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	0	169
8 - Doubtful [Member] | Total agricultural [Member]
Credit quality indicators for commercial and agricultural credit exposures
Total	$ 0	$ 169