Annual report pursuant to Section 13 and 15(d)

Loans Receivable (Details Textual)

v2.4.1.9
Loans Receivable (Details Textual) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2014
Financing Receivable, Modifications [Line Items]    
Financing Receivable, Individually Evaluated for Impairment $ 9,867us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment $ 6,768us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
Land, Buildings and Improvements [Member]    
Financing Receivable, Modifications [Line Items]    
Financing Receivable, Modifications, Recorded Investment 707us-gaap_FinancingReceivableModificationsRecordedInvestment
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandBuildingsAndImprovementsMember 		 
Residential Real Estate [Member]    
Financing Receivable, Modifications [Line Items]    
Financing Receivable, Individually Evaluated for Impairment   588us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_ResidentialRealEstateMember
Financing Receivable, Modifications, Recorded Investment 106us-gaap_FinancingReceivableModificationsRecordedInvestment
/ us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis
= us-gaap_ResidentialRealEstateMember 		 
Impaired Loans [Member]    
Financing Receivable, Modifications [Line Items]    
Impaired Financing Receivable, Unpaid Principal Balance, Total   1,300us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_InvestmentTypeAxis
= nwin_ImpairedLoansMember
Residential Real Estate Including Home Equity [Member]    
Financing Receivable, Modifications [Line Items]    
Financing Receivable, Modifications, Pre-Modification Recorded Investment 792us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2
/ us-gaap_FinancialInstrumentAxis
= nwin_ResidentialRealEstateIncludingHomeEquityMember 		 
Financing Receivable, Modifications, Post-Modification Recorded Investment 770us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
/ us-gaap_FinancialInstrumentAxis
= nwin_ResidentialRealEstateIncludingHomeEquityMember 		 
Impaired Financing Receivable, Unpaid Principal Balance, Total 899us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= nwin_ResidentialRealEstateIncludingHomeEquityMember 		1,258us-gaap_ImpairedFinancingReceivableUnpaidPrincipalBalance
/ us-gaap_FinancialInstrumentAxis
= nwin_ResidentialRealEstateIncludingHomeEquityMember
Financing Receivable, Individually Evaluated for Impairment $ 887us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_FinancialInstrumentAxis
= nwin_ResidentialRealEstateIncludingHomeEquityMember 		$ 97us-gaap_FinancingReceivableIndividuallyEvaluatedForImpairment
/ us-gaap_FinancialInstrumentAxis
= nwin_ResidentialRealEstateIncludingHomeEquityMember