Annual report pursuant to Section 13 and 15(d)

Loans Receivable (Details 5)

v2.4.1.9
Loans Receivable (Details 5) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables on nonaccrual status $ 4,599us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus $ 3,780us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Residential Real Estate Including Home Equity [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables on nonaccrual status 2,443us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
/ us-gaap_FinancialInstrumentAxis
= nwin_ResidentialRealEstateIncludingHomeEquityMember 		2,526us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
/ us-gaap_FinancialInstrumentAxis
= nwin_ResidentialRealEstateIncludingHomeEquityMember
Consumer Loan [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables on nonaccrual status 0us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
/ us-gaap_FinancialInstrumentAxis
= us-gaap_ConsumerLoanMember 		0us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
/ us-gaap_FinancialInstrumentAxis
= us-gaap_ConsumerLoanMember
Commercial Real Estate [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables on nonaccrual status 1,815us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember 		807us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialRealEstateMember
Commercial Participations Purchased [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables on nonaccrual status 103us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
/ us-gaap_FinancialInstrumentAxis
= nwin_CommercialParticipationsPurchasedMember 		0us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
/ us-gaap_FinancialInstrumentAxis
= nwin_CommercialParticipationsPurchasedMember
Commercial Loan [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables on nonaccrual status 238us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember 		447us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
/ us-gaap_FinancialInstrumentAxis
= us-gaap_CommercialLoanMember
Government [Member]    
Financing Receivable, Recorded Investment, Past Due [Line Items]    
Financing receivables on nonaccrual status $ 0us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
/ us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis
= us-gaap_GovernmentMember 		$ 0us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
/ us-gaap_AccountsNotesLoansAndFinancingReceivablesByLegalEntityOfCounterpartyTypeAxis
= us-gaap_GovernmentMember