2.3.0.11 Html 33 153 1 false 4 0 false 3 true false R1.htm 00 - Document - Document and Entity Information Sheet http://isabellabank.com/role/DocumentAndEntityInformation Document and Entity Information false false R2.htm 0110 - Statement - Interim Condensed Consolidated Balance Sheets (Unaudited) Sheet http://isabellabank.com/role/BalanceSheets Interim Condensed Consolidated Balance Sheets (Unaudited) false false R3.htm 0111 - Statement - Interim Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) Sheet http://isabellabank.com/role/BalanceSheetsParenthetical Interim Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) false false R4.htm 0120 - Statement - Interim Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) Sheet http://isabellabank.com/role/StatementsOfStockholdersEquity Interim Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) false false R5.htm 0121 - Statement - Interim Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parenthetical) Sheet http://isabellabank.com/role/StatementsOfStockholdersEquityParenthetical Interim Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parenthetical) false false R6.htm 0130 - Statement - Interim Condensed Consolidated Statements of Income (Unaudited) Sheet http://isabellabank.com/role/StatementsOfIncome Interim Condensed Consolidated Statements of Income (Unaudited) false false R7.htm 0140 - Statement - Interim Condensed Consolidated Statements of Comprehensive Income (Unaudited) Sheet http://isabellabank.com/role/StatementsOfComprehensiveIncome Interim Condensed Consolidated Statements of Comprehensive Income (Unaudited) false false R8.htm 0150 - Statement - Interim Condensed Consolidated Statements of Cash Flows (Unaudited) Sheet http://isabellabank.com/role/StatementsOfCashFlows Interim Condensed Consolidated Statements of Cash Flows (Unaudited) false false R9.htm 0201 - Disclosure - Basis of Presentation Sheet http://isabellabank.com/role/BasisOfPresentation Basis of Presentation false false R10.htm 0202 - Disclosure - Accounting Standards Updates Sheet http://isabellabank.com/role/AccountingStandardsUpdates Accounting Standards Updates false false R11.htm 0203 - Disclosure - Computation of Earnings Per Share Sheet http://isabellabank.com/role/ComputationOfEarningsPerShare Computation of Earnings Per Share false false R12.htm 0204 - Disclosure - Trading Securities Sheet http://isabellabank.com/role/TradingSecurities Trading Securities false false R13.htm 0205 - Disclosure - Available-For-SaleSecurities Sheet http://isabellabank.com/role/AvailableForSaleSecurities Available-For-SaleSecurities false false R14.htm 0206 - Disclosure - Loans And Allowance For Loan Losses Sheet http://isabellabank.com/role/LoansAndAllowanceForLoanLosses Loans And Allowance For Loan Losses false false R15.htm 0207 - Disclosure - Equity Securities Without Readily Determinable Fair Values Sheet http://isabellabank.com/role/EquitySecuritiesWithoutReadilyDeterminableFairValues Equity Securities Without Readily Determinable Fair Values false false R16.htm 0208 - Disclosure - Borrowed Funds Sheet http://isabellabank.com/role/BorrowedFunds Borrowed Funds false false R17.htm 0209 - Disclosure - Other Noninterest Expenses Sheet http://isabellabank.com/role/OtherNoninterestExpenses Other Noninterest Expenses false false R18.htm 0210 - Disclosure - Federal Income Taxes Sheet http://isabellabank.com/role/FederalIncomeTaxes Federal Income Taxes false false R19.htm 0211 - Disclosure - Defined Benefit Pension Plan Sheet http://isabellabank.com/role/DefinedBenefitPensionPlan Defined Benefit Pension Plan false false R20.htm 0212 - Disclosure - Fair Value Sheet http://isabellabank.com/role/FairValue Fair Value false false R21.htm 0213 - Disclosure - Operating Segments Sheet http://isabellabank.com/role/OperatingSegments Operating Segments false false All Reports Book All Reports Process Flow-Through: 0110 - Statement - Interim Condensed Consolidated Balance Sheets (Unaudited) Process Flow-Through: Removing column 'Jun. 30, 2010' Process Flow-Through: Removing column 'Dec. 31, 2009' Process Flow-Through: 0111 - Statement - Interim Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) Process Flow-Through: 0121 - Statement - Interim Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parenthetical) Process Flow-Through: Removing column '3 Months Ended Jun. 30, 2011' Process Flow-Through: Removing column '3 Months Ended Jun. 30, 2010' Process Flow-Through: 0130 - Statement - Interim Condensed Consolidated Statements of Income (Unaudited) Process Flow-Through: 0140 - Statement - Interim Condensed Consolidated Statements of Comprehensive Income (Unaudited) Process Flow-Through: 0150 - Statement - Interim Condensed Consolidated Statements of Cash Flows (Unaudited) isba-20110630.xml isba-20110630.xsd isba-20110630_cal.xml isba-20110630_def.xml isba-20110630_lab.xml isba-20110630_pre.xml true true