Reserve for loans impairments recorded after acquisition as a result of current information and events which result in it being probable that estimated cash flows will be less than previously expected or because actual cash flows are less than cash flows previously expected. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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Loans Receivable and the Allowance for Loan Losses Allowance for Loan Losses and Recorded Investment in Loan Receivables (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivable, allowance for credit losses, individually evaluated for impairment	$ 3,306	$ 4,351
Loans receivable, allowance for credit losses, collectively evaluated for impairment	18,290	16,878
Certain loans acquired in transfer not accounted for as debt securities, allowance for loan losses		621
Allowance for loan losses	22,217	21,850	$ 20,245	$ 19,427
Financing Receivable [Abstract]
Loans receivable, individually evaluated for impairment	38,179	32,178
Loans receivable, collectively evaluated for impairment	2,104,942	2,110,167
Loans receivable,purchased credit impaired		22,798
Loans and leases receivable, gross	2,165,044	2,165,143
Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Allowance for Credit Losses [Line Items]
Certain loans acquired in transfer not accounted for as debt securities, allowance for loan losses	621
Financing Receivable [Abstract]
Loans receivable,purchased credit impaired	21,923
Agricultural Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivable, allowance for credit losses, individually evaluated for impairment	418	62
Loans receivable, allowance for credit losses, collectively evaluated for impairment	2,042	1,941
Allowance for loan losses	2,460	2,003	2,235	1,417
Financing Receivable [Abstract]
Loans receivable, individually evaluated for impairment	3,569	5,339
Loans receivable, collectively evaluated for impairment	105,213	108,004
Loans and leases receivable, gross	108,782	113,343
Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivable, allowance for credit losses, individually evaluated for impairment	1,006	2,066
Loans receivable, allowance for credit losses, collectively evaluated for impairment	5,006	4,199
Allowance for loan losses	6,021	6,274	4,680	5,451
Financing Receivable [Abstract]
Loans receivable, individually evaluated for impairment	17,164	11,434
Loans receivable, collectively evaluated for impairment	441,225	449,380
Loans and leases receivable, gross	458,449	460,970
Commercial Portfolio Segment \| Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Allowance for Credit Losses [Line Items]
Certain loans acquired in transfer not accounted for as debt securities, allowance for loan losses	9	9
Financing Receivable [Abstract]
Loans receivable,purchased credit impaired	60	156
Commercial Real Estate Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivable, allowance for credit losses, individually evaluated for impairment	1,629	1,924
Loans receivable, allowance for credit losses, collectively evaluated for impairment	7,825	7,692
Allowance for loan losses	9,751	9,860	9,713	8,556
Financing Receivable [Abstract]
Loans receivable, individually evaluated for impairment	13,487	11,450
Loans receivable, collectively evaluated for impairment	1,048,865	1,036,049
Loans and leases receivable, gross	1,078,343	1,064,243
Commercial Real Estate Portfolio Segment \| Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Allowance for Credit Losses [Line Items]
Certain loans acquired in transfer not accounted for as debt securities, allowance for loan losses	297	244
Financing Receivable [Abstract]
Loans receivable,purchased credit impaired	15,991	16,744
Residential Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivable, allowance for credit losses, individually evaluated for impairment	253	299
Loans receivable, allowance for credit losses, collectively evaluated for impairment	3,196	2,791
Allowance for loan losses	3,764	3,458	3,429	3,968
Financing Receivable [Abstract]
Loans receivable, individually evaluated for impairment	3,959	3,955
Loans receivable, collectively evaluated for impairment	474,565	480,143
Loans and leases receivable, gross	484,396	489,996
Residential Portfolio Segment \| Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Allowance for Credit Losses [Line Items]
Certain loans acquired in transfer not accounted for as debt securities, allowance for loan losses	315	368
Financing Receivable [Abstract]
Loans receivable,purchased credit impaired	5,872	5,898
Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans receivable, allowance for credit losses, collectively evaluated for impairment	221	255
Allowance for loan losses	221	255	$ 188	$ 409
Financing Receivable [Abstract]
Loans receivable, collectively evaluated for impairment	35,074	36,591
Loans and leases receivable, gross	$ 35,074	$ 36,591