Allowance for Credit Losses - Impaired Loans (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	$ 7,494	$ 2,875
Upaid Principal Balance, With no related allowance recorded	10,402	3,722
Recorded Investment, With an allowance recorded	5,863	14,230
Unpaid Principal Balance, With an allowance recorded	5,955	15,336
Related Allowance	1,007	510
Total Recorded Investment	13,357	17,105
Total Unpaid Principal Balance	16,357	19,058
Average Recorded Investment, With no related allowance recorded	7,278	8,806	5,282
Interest Income Recognized, With no related allowance recorded	0	0	0
Average Recorded Investment, With an allowance recorded	7,090	9,486	10,832
Interest Income Recognized, With an allowance recorded	573	601	411
Average Recorded Investment, Total	14,368	18,292	16,114
Interest Income Recognized, Total	573	601	411
Forgone interest on nonaccrual loans	661	693	954
Commercial
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	350	0
Upaid Principal Balance, With no related allowance recorded	385	0
Recorded Investment, With an allowance recorded	1,177	2,405
Unpaid Principal Balance, With an allowance recorded	1,222	2,405
Related Allowance	469	40
Average Recorded Investment, With no related allowance recorded	329	952	544
Interest Income Recognized, With no related allowance recorded	0	0	0
Average Recorded Investment, With an allowance recorded	1,309	1,581	505
Interest Income Recognized, With an allowance recorded	111	226	181
Commercial and industrial
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	350	0
Upaid Principal Balance, With no related allowance recorded	385	0
Recorded Investment, With an allowance recorded	1,177	2,405
Unpaid Principal Balance, With an allowance recorded	1,222	2,405
Related Allowance	469	40
Average Recorded Investment, With no related allowance recorded	329	952	544
Interest Income Recognized, With no related allowance recorded	0	0	0
Average Recorded Investment, With an allowance recorded	1,309	1,581	505
Interest Income Recognized, With an allowance recorded	111	226	181
Agricultural land and production
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0	0
Upaid Principal Balance, With no related allowance recorded	0	0
Recorded Investment, With an allowance recorded	0	0
Unpaid Principal Balance, With an allowance recorded	0	0
Related Allowance	0	0
Average Recorded Investment, With no related allowance recorded	0	0	0
Interest Income Recognized, With no related allowance recorded	0	0	0
Average Recorded Investment, With an allowance recorded	0	0	0
Interest Income Recognized, With an allowance recorded	0	0	0
Real estate
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	5,111	1,352
Upaid Principal Balance, With no related allowance recorded	7,186	1,888
Recorded Investment, With an allowance recorded	4,429	11,516
Unpaid Principal Balance, With an allowance recorded	4,469	12,608
Related Allowance	465	465
Average Recorded Investment, With no related allowance recorded	4,942	6,287	4,381
Interest Income Recognized, With no related allowance recorded	0	0	0
Average Recorded Investment, With an allowance recorded	5,292	7,268	8,586
Interest Income Recognized, With an allowance recorded	462	375	230
Owner occupied
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	3,160	0
Upaid Principal Balance, With no related allowance recorded	4,159	0
Recorded Investment, With an allowance recorded	385	1,575
Unpaid Principal Balance, With an allowance recorded	425	1,733
Related Allowance	3	165
Average Recorded Investment, With no related allowance recorded	2,321	1,053	1,100
Interest Income Recognized, With no related allowance recorded	0	0	0
Average Recorded Investment, With an allowance recorded	997	633	1,193
Interest Income Recognized, With an allowance recorded	86	0	0
Real estate construction and other land loans
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	1,449	1,352
Upaid Principal Balance, With no related allowance recorded	2,136	1,888
Recorded Investment, With an allowance recorded	4,044	9,941
Unpaid Principal Balance, With an allowance recorded	4,044	10,875
Related Allowance	462	300
Average Recorded Investment, With no related allowance recorded	2,342	4,933	1,690
Interest Income Recognized, With no related allowance recorded	0	0	0
Average Recorded Investment, With an allowance recorded	4,295	6,490	6,544
Interest Income Recognized, With an allowance recorded	329	375	230
Commercial real estate
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	502	0
Upaid Principal Balance, With no related allowance recorded	891	0
Recorded Investment, With an allowance recorded	0	0
Unpaid Principal Balance, With an allowance recorded	0	0
Related Allowance	0	0
Average Recorded Investment, With no related allowance recorded	279	301	1,591
Interest Income Recognized, With no related allowance recorded	0	0	0
Average Recorded Investment, With an allowance recorded	0	145	849
Interest Income Recognized, With an allowance recorded	47	0	0
Agricultural real estate
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0	0
Upaid Principal Balance, With no related allowance recorded	0	0
Recorded Investment, With an allowance recorded	0	0
Unpaid Principal Balance, With an allowance recorded	0	0
Related Allowance	0	0
Average Recorded Investment, With no related allowance recorded	0	0	0
Interest Income Recognized, With no related allowance recorded	0	0	0
Average Recorded Investment, With an allowance recorded	0	0	0
Interest Income Recognized, With an allowance recorded	0	0	0
Other real estate
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	0	0
Upaid Principal Balance, With no related allowance recorded	0	0
Recorded Investment, With an allowance recorded	0	0
Unpaid Principal Balance, With an allowance recorded	0	0
Related Allowance	0	0
Average Recorded Investment, With no related allowance recorded	0	0	0
Interest Income Recognized, With no related allowance recorded	0	0	0
Average Recorded Investment, With an allowance recorded	0	0	0
Interest Income Recognized, With an allowance recorded	0	0	0
Consumer
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	2,033	1,523
Upaid Principal Balance, With no related allowance recorded	2,831	1,834
Recorded Investment, With an allowance recorded	257	309
Unpaid Principal Balance, With an allowance recorded	264	323
Related Allowance	73	5
Average Recorded Investment, With no related allowance recorded	2,007	1,567	357
Interest Income Recognized, With no related allowance recorded	0	0	0
Average Recorded Investment, With an allowance recorded	489	637	1,741
Interest Income Recognized, With an allowance recorded	0	0	0
Equity loans and lines of credit
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	2,029	1,523
Upaid Principal Balance, With no related allowance recorded	2,826	1,834
Recorded Investment, With an allowance recorded	257	309
Unpaid Principal Balance, With an allowance recorded	264	323
Related Allowance	73	5
Average Recorded Investment, With no related allowance recorded	1,998	1,561	357
Interest Income Recognized, With no related allowance recorded	0	0	0
Average Recorded Investment, With an allowance recorded	489	600	1,640
Interest Income Recognized, With an allowance recorded	0	0	0
Consumer and installment
Financing Receivable, Impaired [Line Items]
Recorded Investment, With no related allowance recorded	4	0
Upaid Principal Balance, With no related allowance recorded	5	0
Recorded Investment, With an allowance recorded	0	0
Unpaid Principal Balance, With an allowance recorded	0	0
Related Allowance	0	0
Average Recorded Investment, With no related allowance recorded	9	6	0
Interest Income Recognized, With no related allowance recorded	0	0	0
Average Recorded Investment, With an allowance recorded	0	37	101
Interest Income Recognized, With an allowance recorded	$ 0	$ 0	$ 0

Name:	us-gaap_FinancingReceivableImpairedLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

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

+ Details

Name:	us-gaap_ImpairedFinancingReceivableAverageRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableInterestIncomeAccrualMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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 14A

-Subparagraph (b)

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

+ Details

Name:	us-gaap_ImpairedFinancingReceivableRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of allowance for credit losses related to recorded investment.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableRelatedAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of average investment of impaired financing receivables for which there is no related allowance for credit losses.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceAverageRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceInterestIncomeAccrualMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of investment in impaired financing receivables for which there is no related allowance for credit losses.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableWithNoRelatedAllowanceUnpaidPrincipalBalance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of average investment of impaired financing receivables for which there is a related allowance for credit losses.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceAverageRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceInterestIncomeAccrualMethod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceRecordedInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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

+ References

+ Details

Name:	us-gaap_ImpairedFinancingReceivableWithRelatedAllowanceUnpaidPrincipalBalance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 114

-Paragraph 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher OTS

-Name Federal Regulation (FR)

-Number Title 12

-Section 563c.102

-Paragraph 8

-Subparagraph j(ii)

-Chapter V

-Subsection I

-LegacyDoc This is a non-GAAP reference that was included in the 2009 taxonomy. It will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 15

-Paragraph 40

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_LoansAndLeasesReceivableImpairedInterestLostOnNonaccrualLoans
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration