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    <Log type="Info">Element us-gaap_OtherThanTemporaryImpairmentCreditLossesRecognizedInEarningsCreditLossesOnDebtSecuritiesHeld had a mix of decimals attribute values: -3 0.</Log>
    <Log type="Info">Element us-gaap_OtherThanTemporaryImpairmentLossesInvestmentsPortionRecognizedInEarningsNet had a mix of decimals attribute values: -5 0.</Log>
    <Log type="Info">Element us-gaap_StockRepurchasedDuringPeriodValue had a mix of decimals attribute values: -5 -3.</Log>
    <Log type="Info">'Monetary' elements on report '4032 - Disclosure - Marketable Securities (Details 3)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4033 - Disclosure - Marketable Securities (Details 4)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4036 - Disclosure - Marketable Securities (Details 7)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4039 - Disclosure - Marketable Securities (Details 10)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4040 - Disclosure - Loans Receivable (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4042 - Disclosure - Loans Receivable (Details 3)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4046 - Disclosure - Loans Receivable (Details 7)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4080 - Disclosure - Premises and Equipment (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4081 - Disclosure - Premises and Equipment (Details 2)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4100 - Disclosure - Deposits (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4110 - Disclosure - Borrowed Funds (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4150 - Disclosure - Employee Benefit Plans (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4151 - Disclosure - Employee Benefit Plans (Details 2)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4152 - Disclosure - Employee Benefit Plans (Details 3)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4153 - Disclosure - Employee Benefit Plans (Details 4)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4154 - Disclosure - Employee Benefit Plans (Details 5)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4170 - Disclosure - Regulatory Capital Requirements (Details)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">'Monetary' elements on report '4201 - Disclosure - Parent Company Only Financial Statements - Condensed (Details2)' had a mix of different decimal attribute values.</Log>
    <Log type="Info">Process Flow-Through: 0010 - Statement - CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2009'</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2008'</Log>
    <Log type="Info">Process Flow-Through: 0015 - Statement - CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION (Parenthetical)</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2009'</Log>
    <Log type="Info">	Process Flow-Through: Removing column 'Dec. 31, 2008'</Log>
    <Log type="Info">Process Flow-Through: 0020 - Statement - CONSOLIDATED STATEMENTS OF INCOME</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Dec. 31, 2011'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Sep. 30, 2011'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Jun. 30, 2011'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Mar. 31, 2011'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Dec. 31, 2010'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Sep. 30, 2010'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Jun. 30, 2010'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Mar. 31, 2010'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Dec. 31, 2009'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Sep. 30, 2009'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Jun. 30, 2009'</Log>
    <Log type="Info">	Process Flow-Through: Removing column '3 Months Ended
Mar. 31, 2009'</Log>
    <Log type="Info">Process Flow-Through: 0035 - Statement - CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Parenthetical)</Log>
    <Log type="Info">Process Flow-Through: 0040 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS</Log>
    <Log type="Info">Process Flow-Through: 0045 - Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical)</Log>
  </Logs>
  <InputFiles>
    <File>nwbi-20111231.xml</File>
    <File>nwbi-20111231.xsd</File>
    <File>nwbi-20111231_cal.xml</File>
    <File>nwbi-20111231_def.xml</File>
    <File>nwbi-20111231_lab.xml</File>
    <File>nwbi-20111231_pre.xml</File>
  </InputFiles>
  <SupplementalFiles />
  <BaseTaxonomies />
  <HasPresentationLinkbase>true</HasPresentationLinkbase>
  <HasCalculationLinkbase>true</HasCalculationLinkbase>
</FilingSummary>
