Loans and ALLL (Summary of information pertaining to impaired loans) (Details) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Information pertaining to impaired loans    
Impaired loans with a valuation allowance, Outstanding Balance $ 21,468 $ 20,468
Impaired loans without a valuation allowance, Outstanding Balance 8,307  
Impaired loans, Outstanding Balance 29,775 25,958
Impaired loans with a valuation allowance, Unpaid Principal Balance 22,878 21,977
Impaired loans without a valuation allowance, Unpaid Principal Balance 9,743  
Impaired loans, Unpaid Principal Balance 32,621 28,716
Impaired loans with a valuation allowance, Valuation Allowance 4,352 3,937
Impaired loans, Valuation Allowance 4,352 3,937
Impaired loans with a valuation allowance, Average Outstanding Balance 19,470 18,555
Impaired loans without a valuation allowance, Average Outstanding Balance 6,230  
Impaired loans, Average Outstanding Balance 25,700 25,905
Impaired loans with a valuation allowance, Interest Income Recognized 899 796
Impaired loans without a valuation allowance, Interest Income Recognized 459  
Impaired loans, Interest Income Recognized 1,358 1,230
Commercial real estate [Member]
    
Information pertaining to impaired loans    
Impaired loans with a valuation allowance, Outstanding Balance 6,748 7,295
Impaired loans without a valuation allowance, Outstanding Balance 5,622 3,749
Impaired loans with a valuation allowance, Unpaid Principal Balance 6,888 7,536
Impaired loans without a valuation allowance, Unpaid Principal Balance 6,499 4,408
Impaired loans with a valuation allowance, Valuation Allowance 1,915 1,653
Impaired loans with a valuation allowance, Average Outstanding Balance 7,256 6,155
Impaired loans without a valuation allowance, Average Outstanding Balance 4,312 5,867
Impaired loans with a valuation allowance, Interest Income Recognized 400 237
Impaired loans without a valuation allowance, Interest Income Recognized 337 321
Commercial other [Member]
    
Information pertaining to impaired loans    
Impaired loans with a valuation allowance, Outstanding Balance 521 2,140
Impaired loans without a valuation allowance, Outstanding Balance 925 1,272
Impaired loans with a valuation allowance, Unpaid Principal Balance 521 2,140
Impaired loans without a valuation allowance, Unpaid Principal Balance 1,035 1,433
Impaired loans with a valuation allowance, Valuation Allowance 120 397
Impaired loans with a valuation allowance, Average Outstanding Balance 879 1,437
Impaired loans without a valuation allowance, Average Outstanding Balance 989 819
Impaired loans with a valuation allowance, Interest Income Recognized 51 93
Impaired loans without a valuation allowance, Interest Income Recognized 83 87
Agricultural real estate [Member]
    
Information pertaining to impaired loans    
Impaired loans with a valuation allowance, Outstanding Balance 90 91
Impaired loans without a valuation allowance, Outstanding Balance 1,370 0
Impaired loans with a valuation allowance, Unpaid Principal Balance 90 91
Impaired loans without a valuation allowance, Unpaid Principal Balance 1,370 0
Impaired loans with a valuation allowance, Valuation Allowance 30 32
Impaired loans with a valuation allowance, Average Outstanding Balance 91 413
Impaired loans without a valuation allowance, Average Outstanding Balance 320 183
Impaired loans with a valuation allowance, Interest Income Recognized 4 0
Impaired loans without a valuation allowance, Interest Income Recognized 28 0
Agricultural other [Member]
    
Information pertaining to impaired loans    
Impaired loans with a valuation allowance, Outstanding Balance 0 420
Impaired loans without a valuation allowance, Outstanding Balance 78 212
Impaired loans with a valuation allowance, Unpaid Principal Balance 0 420
Impaired loans without a valuation allowance, Unpaid Principal Balance 198 332
Impaired loans with a valuation allowance, Valuation Allowance 0 59
Impaired loans with a valuation allowance, Average Outstanding Balance 53 1,555
Impaired loans without a valuation allowance, Average Outstanding Balance 357 201
Impaired loans with a valuation allowance, Interest Income Recognized 0 54
Impaired loans without a valuation allowance, Interest Income Recognized (7) 4
Residential real estate senior liens [Member]
    
Information pertaining to impaired loans    
Impaired loans with a valuation allowance, Outstanding Balance 14,061 10,450
Impaired loans without a valuation allowance, Outstanding Balance   182
Impaired loans with a valuation allowance, Unpaid Principal Balance 15,315 11,672
Impaired loans without a valuation allowance, Unpaid Principal Balance   482
Impaired loans with a valuation allowance, Valuation Allowance 2,278 1,783
Impaired loans with a valuation allowance, Average Outstanding Balance 11,111 8,861
Impaired loans without a valuation allowance, Average Outstanding Balance   190
Impaired loans with a valuation allowance, Interest Income Recognized 442 406
Impaired loans without a valuation allowance, Interest Income Recognized   16
Residential real estate junior liens [Member]
    
Information pertaining to impaired loans    
Impaired loans with a valuation allowance, Outstanding Balance 48 72
Impaired loans with a valuation allowance, Unpaid Principal Balance 64 118
Impaired loans with a valuation allowance, Valuation Allowance 9 13
Impaired loans with a valuation allowance, Average Outstanding Balance 80 134
Impaired loans with a valuation allowance, Interest Income Recognized 2 6
Home equity lines of credit [Member]
    
Information pertaining to impaired loans    
Impaired loans without a valuation allowance, Outstanding Balance 193 75
Impaired loans without a valuation allowance, Unpaid Principal Balance 493 84
Impaired loans without a valuation allowance, Average Outstanding Balance 180 90
Impaired loans without a valuation allowance, Interest Income Recognized 16 6
Consumer secured [Member]
    
Information pertaining to impaired loans    
Impaired loans without a valuation allowance, Outstanding Balance 119 5,490
Impaired loans without a valuation allowance, Unpaid Principal Balance 148 6,739
Impaired loans without a valuation allowance, Average Outstanding Balance 72 7,350
Impaired loans without a valuation allowance, Interest Income Recognized 2 434
Total commercial [Member]
    
Information pertaining to impaired loans    
Impaired loans, Outstanding Balance 13,816 14,456
Impaired loans, Unpaid Principal Balance 14,943 15,517
Impaired loans, Valuation Allowance 2,035 2,050
Impaired loans, Average Outstanding Balance 13,436 14,278
Impaired loans, Interest Income Recognized 871 738
Agricultural [Member]
    
Information pertaining to impaired loans    
Impaired loans, Outstanding Balance 1,538 723
Impaired loans, Unpaid Principal Balance 1,658 843
Impaired loans, Valuation Allowance 30 91
Impaired loans, Average Outstanding Balance 821 2,352
Impaired loans, Interest Income Recognized 25 58
Residential Real Estate [Member]
    
Information pertaining to impaired loans    
Impaired loans, Outstanding Balance 14,302 10,704
Impaired loans, Unpaid Principal Balance 15,872 12,272
Impaired loans, Valuation Allowance 2,287 1,796
Impaired loans, Average Outstanding Balance 11,371 9,185
Impaired loans, Interest Income Recognized 460 428
Consumer [Member]
    
Information pertaining to impaired loans    
Impaired loans, Outstanding Balance 119 75
Impaired loans, Unpaid Principal Balance 148 84
Impaired loans, Valuation Allowance 0 0
Impaired loans, Average Outstanding Balance 72 90
Impaired loans, Interest Income Recognized $ 2 $ 6