3.2.0.727 html 922 429 1 true 110 0 false 7 false false R1.htm 101 - Document - Document and Entity Information Sheet http://www.bankozarks.com/taxonomy/role/DocumentandEntityInformation Document and Entity Information Cover 1 false false R2.htm 103 - Statement - Consolidated Balance Sheets Sheet http://www.bankozarks.com/taxonomy/role/StatementOfFinancialPositionUnclassified-DepositBasedOperations Consolidated Balance Sheets Statements 2 false false R3.htm 104 - Statement - Consolidated Balance Sheets (Parenthetical) Sheet http://www.bankozarks.com/taxonomy/role/StatementOfFinancialPositionUnclassified-DepositBasedOperationsParenthetical Consolidated Balance Sheets (Parenthetical) Statements 3 false false R4.htm 105 - Statement - Consolidated Statements of Income (Unaudited) Sheet http://www.bankozarks.com/taxonomy/role/StatementOfIncomeInterestBasedRevenue Consolidated Statements of Income (Unaudited) Statements 4 false false R5.htm 106 - Statement - Consolidated Statements of Comprehensive Income (Unaudited) Sheet http://www.bankozarks.com/taxonomy/role/StatementOfOtherComprehensiveIncome Consolidated Statements of Comprehensive Income (Unaudited) Statements 5 false false R6.htm 107 - Statement - Consolidated Statements of Stockholders' Equity (Unaudited) Sheet http://www.bankozarks.com/taxonomy/role/StatementOfShareholdersEquityAndOtherComprehensiveIncome Consolidated Statements of Stockholders' Equity (Unaudited) Statements 6 false false R7.htm 108 - Statement - Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) Sheet http://www.bankozarks.com/taxonomy/role/StatementOfShareholdersEquityAndOtherComprehensiveIncomeParenthetical Consolidated Statements of Stockholders' Equity (Unaudited) (Parenthetical) Statements 7 false false R8.htm 109 - Statement - Consolidated Statements of Cash Flows (Unaudited) Sheet http://www.bankozarks.com/taxonomy/role/StatementOfCashFlowsIndirectDepositBasedOperations Consolidated Statements of Cash Flows (Unaudited) Statements 8 false false R9.htm 110 - Disclosure - Organization and Principles of Consolidation Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsOrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock Organization and Principles of Consolidation Notes 9 false false R10.htm 111 - Disclosure - Basis of Presentation Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsBusinessDescriptionAndBasisOfPresentationTextBlock Basis of Presentation Notes 10 false false R11.htm 112 - Disclosure - Acquisitions Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsBusinessCombinationDisclosureTextBlock Acquisitions Notes 11 false false R12.htm 113 - Disclosure - Earnings Per Common Share ("EPS") Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsEarningsPerShareTextBlock Earnings Per Common Share ("EPS") Notes 12 false false R13.htm 114 - Disclosure - Investment Securities Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsAvailableForSaleSecuritiesTextBlock Investment Securities Notes 13 false false R14.htm 115 - Disclosure - Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsAllowanceForLoanAndLeaseLossesAlllTextBlock Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators Notes 14 false false R15.htm 116 - Disclosure - Income Taxes Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsIncomeTaxDisclosureTextBlock Income Taxes Notes 15 false false R16.htm 117 - Disclosure - Supplemental Data for Cash Flows Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsCashFlowSupplementalDisclosuresTextBlock Supplemental Data for Cash Flows Notes 16 false false R17.htm 118 - Disclosure - Guarantees and Commitments Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsCommitmentsContingenciesAndGuaranteesTextBlock Guarantees and Commitments Notes 17 false false R18.htm 119 - Disclosure - Subordinated Debentures Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsSubordinatedBorrowingsDisclosureTextBlock Subordinated Debentures Notes 18 false false R19.htm 120 - Disclosure - Stock-Based Compensation Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsDisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock Stock-Based Compensation Notes 19 false false R20.htm 121 - Disclosure - Fair Value Measurements Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsFairValueDisclosuresTextBlock Fair Value Measurements Notes 20 false false R21.htm 122 - Disclosure - Fair Value of Financial Instruments Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsDerivativesAndFairValueTextBlock Fair Value of Financial Instruments Notes 21 false false R22.htm 123 - Disclosure - Repurchase Agreements With Customers Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsRepurchaseAgreementsResaleAgreementsSecuritiesBorrowedAndSecuritiesLoanedDisclosureTextBlock Repurchase Agreements With Customers Notes 22 false false R23.htm 124 - Disclosure - Changes in and Reclassifications From Accumulated Other Comprehensive Income ("AOCI") Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsComprehensiveIncomeNoteTextBlock Changes in and Reclassifications From Accumulated Other Comprehensive Income ("AOCI") Notes 23 false false R24.htm 125 - Disclosure - Other Operating Expenses Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsOtherOperatingIncomeAndExpenseTextBlock Other Operating Expenses Notes 24 false false R25.htm 126 - Disclosure - Subsequent Event Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsSubsequentEventsTextBlock Subsequent Event Notes 25 false false R26.htm 127 - Disclosure - Recent Accounting Pronouncements Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsNewAccountingPronouncementsAndChangesInAccountingPrinciplesTextBlock Recent Accounting Pronouncements Notes 26 false false R27.htm 128 - Disclosure - Acquisitions (Tables) Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsBusinessCombinationDisclosureTextBlockTables Acquisitions (Tables) Tables http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsBusinessCombinationDisclosureTextBlock 27 false false R28.htm 129 - Disclosure - Earnings Per Common Share ("EPS") (Tables) Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsEarningsPerShareTextBlockTables Earnings Per Common Share ("EPS") (Tables) Tables http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsEarningsPerShareTextBlock 28 false false R29.htm 130 - Disclosure - Investment Securities (Tables) Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsAvailableForSaleSecuritiesTextBlockTables Investment Securities (Tables) Tables http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsAvailableForSaleSecuritiesTextBlock 29 false false R30.htm 131 - Disclosure - Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators (Tables) Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsAllowanceForLoanAndLeaseLossesAlllTextBlockTables Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators (Tables) Tables http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsAllowanceForLoanAndLeaseLossesAlllTextBlock 30 false false R31.htm 132 - Disclosure - Income Taxes (Tables) Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsIncomeTaxDisclosureTextBlockTables Income Taxes (Tables) Tables http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsIncomeTaxDisclosureTextBlock 31 false false R32.htm 133 - Disclosure - Supplemental Data for Cash Flows (Tables) Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsCashFlowSupplementalDisclosuresTextBlockTables Supplemental Data for Cash Flows (Tables) Tables http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsCashFlowSupplementalDisclosuresTextBlock 32 false false R33.htm 134 - Disclosure - Guarantees and Commitments (Tables) Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsCommitmentsContingenciesAndGuaranteesTextBlockTables Guarantees and Commitments (Tables) Tables http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsCommitmentsContingenciesAndGuaranteesTextBlock 33 false false R34.htm 135 - Disclosure - Subordinated Debentures (Tables) Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsSubordinatedBorrowingsDisclosureTextBlockTables Subordinated Debentures (Tables) Tables http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsSubordinatedBorrowingsDisclosureTextBlock 34 false false R35.htm 136 - Disclosure - Stock-Based Compensation (Tables) Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsDisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlockTables Stock-Based Compensation (Tables) Tables http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsDisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock 35 false false R36.htm 137 - Disclosure - Fair Value Measurements (Tables) Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsFairValueDisclosuresTextBlockTables Fair Value Measurements (Tables) Tables http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsFairValueDisclosuresTextBlock 36 false false R37.htm 138 - Disclosure - Fair Value of Financial Instruments (Tables) Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsDerivativesAndFairValueTextBlockTables Fair Value of Financial Instruments (Tables) Tables http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsDerivativesAndFairValueTextBlock 37 false false R38.htm 139 - Disclosure - Changes in and Reclassifications From Accumulated Other Comprehensive Income ("AOCI") (Tables) Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsComprehensiveIncomeNoteTextBlockTables Changes in and Reclassifications From Accumulated Other Comprehensive Income ("AOCI") (Tables) Tables http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsComprehensiveIncomeNoteTextBlock 38 false false R39.htm 140 - Disclosure - Other Operating Expenses (Tables) Sheet http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsOtherOperatingIncomeAndExpenseTextBlockTables Other Operating Expenses (Tables) Tables http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsOtherOperatingIncomeAndExpenseTextBlock 39 false false R40.htm 141 - Disclosure - Organization and Principles of Consolidation - Additional Information (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureOrganizationAndPrinciplesOfConsolidationAdditionalInformation Organization and Principles of Consolidation - Additional Information (Detail) Details 40 false false R41.htm 142 - Disclosure - Acquisitions - Additional Information (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureAcquisitionsAdditionalInformation Acquisitions - Additional Information (Detail) Details 41 false false R42.htm 143 - Disclosure - Acquisitions - Summary of Assets Acquired and Liabilities Assumed in Acquisition (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureAcquisitionsSummaryOfAssetsAcquiredAndLiabilitiesAssumedInAcquisition Acquisitions - Summary of Assets Acquired and Liabilities Assumed in Acquisition (Detail) Details 42 false false R43.htm 144 - Disclosure - Acquisitions - Summary of Financial Statement Captions Impacted by Recast Adjustments (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureAcquisitionsSummaryOfFinancialStatementCaptionsImpactedByRecastAdjustments Acquisitions - Summary of Financial Statement Captions Impacted by Recast Adjustments (Detail) Details 43 false false R44.htm 145 - Disclosure - Acquisitions - Summary of Supplemental Pro-forma Information (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureAcquisitionsSummaryOfSupplementalProformaInformation Acquisitions - Summary of Supplemental Pro-forma Information (Detail) Details 44 false false R45.htm 146 - Disclosure - Earnings Per Common Share ("EPS") - Additional Information (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureEarningsPerCommonShareEPSAdditionalInformation Earnings Per Common Share ("EPS") - Additional Information (Detail) Details http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsEarningsPerShareTextBlockTables 45 false false R46.htm 147 - Disclosure - Earnings Per Common Share ("EPS") - Schedule of Calculation of Numerator and Denominator in Basic and Diluted Earnings Per Share (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureEarningsPerCommonShareEPSScheduleOfCalculationOfNumeratorAndDenominatorInBasicAndDilutedEarningsPerShare Earnings Per Common Share ("EPS") - Schedule of Calculation of Numerator and Denominator in Basic and Diluted Earnings Per Share (Detail) Details http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsEarningsPerShareTextBlockTables 46 false false R47.htm 148 - Disclosure - Investment Securities - Summary of Amortized Cost and Estimated Fair Values of Investment Securities (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureInvestmentSecuritiesSummaryOfAmortizedCostAndEstimatedFairValuesOfInvestmentSecurities Investment Securities - Summary of Amortized Cost and Estimated Fair Values of Investment Securities (Detail) Details 47 false false R48.htm 149 - Disclosure - Investment Securities - Gross Unrealized Losses and Estimated Fair Value of Investment Securities (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureInvestmentSecuritiesGrossUnrealizedLossesAndEstimatedFairValueOfInvestmentSecurities Investment Securities - Gross Unrealized Losses and Estimated Fair Value of Investment Securities (Detail) Details 48 false false R49.htm 150 - Disclosure - Investment Securities - Amortized Cost and Estimated Fair Value of Investment Securities AFS by Maturity or Estimated Date of Repayment (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureInvestmentSecuritiesAmortizedCostAndEstimatedFairValueOfInvestmentSecuritiesAFSByMaturityOrEstimatedDateOfRepayment Investment Securities - Amortized Cost and Estimated Fair Value of Investment Securities AFS by Maturity or Estimated Date of Repayment (Detail) Details 49 false false R50.htm 151 - Disclosure - Investment Securities - Sales Activities of Company's Investment Securities AFS are Summarized (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureInvestmentSecuritiesSalesActivitiesOfCompanysInvestmentSecuritiesAFSAreSummarized Investment Securities - Sales Activities of Company's Investment Securities AFS are Summarized (Detail) Details 50 false false R51.htm 152 - Disclosure - Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Schedule of Activity Within Allowance for Loan and Lease Losses (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureAllowanceForLoanAndLeaseLossesALLLAndCreditQualityIndicatorsScheduleOfActivityWithinAllowanceForLoanAndLeaseLosses Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Schedule of Activity Within Allowance for Loan and Lease Losses (Detail) Details http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsAllowanceForLoanAndLeaseLossesAlllTextBlockTables 51 false false R52.htm 153 - Disclosure - Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Additional Information (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureAllowanceForLoanAndLeaseLossesALLLAndCreditQualityIndicatorsAdditionalInformation Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Additional Information (Detail) Details http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsAllowanceForLoanAndLeaseLossesAlllTextBlockTables 52 false false R53.htm 154 - Disclosure - Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Summary of Company's Allowance for Loan and Lease Losses (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureAllowanceForLoanAndLeaseLossesALLLAndCreditQualityIndicatorsSummaryOfCompanysAllowanceForLoanAndLeaseLosses Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Summary of Company's Allowance for Loan and Lease Losses (Detail) Details http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsAllowanceForLoanAndLeaseLossesAlllTextBlockTables 53 false false R54.htm 155 - Disclosure - Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Summary of Allowance for Loan and Lease Losses and Recorded Investment in Non-Purchased Loans and Leases (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureAllowanceForLoanAndLeaseLossesALLLAndCreditQualityIndicatorsSummaryOfAllowanceForLoanAndLeaseLossesAndRecordedInvestmentInNonPurchasedLoansAndLeases Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Summary of Allowance for Loan and Lease Losses and Recorded Investment in Non-Purchased Loans and Leases (Detail) Details http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsAllowanceForLoanAndLeaseLossesAlllTextBlockTables 54 false false R55.htm 156 - Disclosure - Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Schedule of Impaired Non-purchased Loans and Leases, FDIC Loss Share Agreements (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureAllowanceForLoanAndLeaseLossesALLLAndCreditQualityIndicatorsScheduleOfImpairedNonpurchasedLoansAndLeasesFDICLossShareAgreements Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Schedule of Impaired Non-purchased Loans and Leases, FDIC Loss Share Agreements (Detail) Details http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsAllowanceForLoanAndLeaseLossesAlllTextBlockTables 55 false false R56.htm 157 - Disclosure - Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Summary of Credit Quality Indicators for Loans and Leases, Including Purchased and Non-Purchased Loans and Leases (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureAllowanceForLoanAndLeaseLossesALLLAndCreditQualityIndicatorsSummaryOfCreditQualityIndicatorsForLoansAndLeasesIncludingPurchasedAndNonPurchasedLoansAndLeases Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Summary of Credit Quality Indicators for Loans and Leases, Including Purchased and Non-Purchased Loans and Leases (Detail) Details http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsAllowanceForLoanAndLeaseLossesAlllTextBlockTables 56 false false R57.htm 158 - Disclosure - Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Schedule of Aging Analysis Past Due Loans and Leases, Loans Purchased and Non-Purchased by FDIC Loss Share Agreements (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureAllowanceForLoanAndLeaseLossesALLLAndCreditQualityIndicatorsScheduleOfAgingAnalysisPastDueLoansAndLeasesLoansPurchasedAndNonPurchasedByFDICLossShareAgreements Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Schedule of Aging Analysis Past Due Loans and Leases, Loans Purchased and Non-Purchased by FDIC Loss Share Agreements (Detail) Details http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsAllowanceForLoanAndLeaseLossesAlllTextBlockTables 57 false false R58.htm 159 - Disclosure - Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Schedule of Aging Analysis Past Due Loans and Leases, Loans Purchased and Non-Purchased by FDIC Loss Share Agreements (Parenthetical) (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureAllowanceForLoanAndLeaseLossesALLLAndCreditQualityIndicatorsScheduleOfAgingAnalysisPastDueLoansAndLeasesLoansPurchasedAndNonPurchasedByFDICLossShareAgreementsParenthetical Allowance for Loan and Lease Losses ("ALLL") and Credit Quality Indicators - Schedule of Aging Analysis Past Due Loans and Leases, Loans Purchased and Non-Purchased by FDIC Loss Share Agreements (Parenthetical) (Detail) Details http://www.bankozarks.com/taxonomy/role/NotesToFinancialStatementsAllowanceForLoanAndLeaseLossesAlllTextBlockTables 58 false false R59.htm 160 - Disclosure - Income Taxes - Types of Temporary Differences Between Tax Basis of Assets and Liabilities (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureIncomeTaxesTypesOfTemporaryDifferencesBetweenTaxBasisOfAssetsAndLiabilities Income Taxes - Types of Temporary Differences Between Tax Basis of Assets and Liabilities (Detail) Details 59 false false R60.htm 161 - Disclosure - Income Taxes - Additional Information (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureIncomeTaxesAdditionalInformation Income Taxes - Additional Information (Detail) Details 60 false false R61.htm 162 - Disclosure - Supplemental Data for Cash Flows - Schedule of Supplemental Cash Flow Information (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureSupplementalDataForCashFlowsScheduleOfSupplementalCashFlowInformation Supplemental Data for Cash Flows - Schedule of Supplemental Cash Flow Information (Detail) Details 61 false false R62.htm 163 - Disclosure - Guarantees and Commitments - Additional Information (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureGuaranteesAndCommitmentsAdditionalInformation Guarantees and Commitments - Additional Information (Detail) Details 62 false false R63.htm 164 - Disclosure - Guarantees and Commitments - Contractual Maturities (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureGuaranteesAndCommitmentsContractualMaturities Guarantees and Commitments - Contractual Maturities (Detail) Details 63 false false R64.htm 165 - Disclosure - Subordinated Debentures - Schedule of Issues of Trust Preferred Securities Outstanding and Subordinated Debentures Owed to Trust (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureSubordinatedDebenturesScheduleOfIssuesOfTrustPreferredSecuritiesOutstandingAndSubordinatedDebenturesOwedToTrust Subordinated Debentures - Schedule of Issues of Trust Preferred Securities Outstanding and Subordinated Debentures Owed to Trust (Detail) Details 64 false false R65.htm 166 - Disclosure - Subordinated Debentures - Additional Information (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureSubordinatedDebenturesAdditionalInformation Subordinated Debentures - Additional Information (Detail) Details 65 false false R66.htm 167 - Disclosure - Stock-Based Compensation - Additional Information (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformation Stock-Based Compensation - Additional Information (Detail) Details 66 false false R67.htm 168 - Disclosure - Stock-Based Compensation - Summary of Stock Option Activity (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStockOptionActivity Stock-Based Compensation - Summary of Stock Option Activity (Detail) Details 67 false false R68.htm 169 - Disclosure - Stock-Based Compensation - Summary of Stock Option Activity (Parenthetical) (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureStockBasedCompensationSummaryOfStockOptionActivityParenthetical Stock-Based Compensation - Summary of Stock Option Activity (Parenthetical) (Detail) Details 68 false false R69.htm 170 - Disclosure - Stock-Based Compensation - Summary of Non-Vested Restricted Stock Activity (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureStockBasedCompensationSummaryOfNonVestedRestrictedStockActivity Stock-Based Compensation - Summary of Non-Vested Restricted Stock Activity (Detail) Details 69 false false R70.htm 171 - Disclosure - Fair Value Measurements - Additional Information (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureFairValueMeasurementsAdditionalInformation Fair Value Measurements - Additional Information (Detail) Details 70 false false R71.htm 172 - Disclosure - Fair Value Measurements - Assets and Liabilities at Fair Value (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureFairValueMeasurementsAssetsAndLiabilitiesAtFairValue Fair Value Measurements - Assets and Liabilities at Fair Value (Detail) Details 71 false false R72.htm 173 - Disclosure - Fair Value Measurements - Assets and Liabilities at Fair Value (Parenthetical) (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureFairValueMeasurementsAssetsAndLiabilitiesAtFairValueParenthetical Fair Value Measurements - Assets and Liabilities at Fair Value (Parenthetical) (Detail) Details 72 false false R73.htm 174 - Disclosure - Fair Value Measurements - Schedule of Information Related to Level 3 Non-Recurring Fair Value Measurements (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureFairValueMeasurementsScheduleOfInformationRelatedToLevel3NonRecurringFairValueMeasurements Fair Value Measurements - Schedule of Information Related to Level 3 Non-Recurring Fair Value Measurements (Detail) Details 73 false false R74.htm 175 - Disclosure - Fair Value Measurements - Assets Measured at Fair Value on Recurring Basis Utilizing Level 3 Inputs (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureFairValueMeasurementsAssetsMeasuredAtFairValueOnRecurringBasisUtilizingLevel3Inputs Fair Value Measurements - Assets Measured at Fair Value on Recurring Basis Utilizing Level 3 Inputs (Detail) Details 74 false false R75.htm 176 - Disclosure - Fair Value of Financial Instruments - Additional Information (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureFairValueOfFinancialInstrumentsAdditionalInformation Fair Value of Financial Instruments - Additional Information (Detail) Details 75 false false R76.htm 177 - Disclosure - Fair Value of Financial Instruments - Estimated Fair Values of Financial Instruments (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureFairValueOfFinancialInstrumentsEstimatedFairValuesOfFinancialInstruments Fair Value of Financial Instruments - Estimated Fair Values of Financial Instruments (Detail) Details 76 false false R77.htm 178 - Disclosure - Repurchase Agreements With Customers - Additional Information (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureRepurchaseAgreementsWithCustomersAdditionalInformation Repurchase Agreements With Customers - Additional Information (Detail) Details 77 false false R78.htm 179 - Disclosure - Changes in and Reclassifications from Accumulated Other Comprehensive Income ("AOCI") - Changes in Accumulated Other Comprehensive Income (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureChangesInAndReclassificationsFromAccumulatedOtherComprehensiveIncomeAOCIChangesInAccumulatedOtherComprehensiveIncome Changes in and Reclassifications from Accumulated Other Comprehensive Income ("AOCI") - Changes in Accumulated Other Comprehensive Income (Detail) Details 78 false false R79.htm 180 - Disclosure - Other Operating Expenses - Summary of Other Operating Expenses (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureOtherOperatingExpensesSummaryOfOtherOperatingExpenses Other Operating Expenses - Summary of Other Operating Expenses (Detail) Details 79 false false R80.htm 181 - Disclosure - Subsequent Events - Additional Information (Detail) Sheet http://www.bankozarks.com/taxonomy/role/DisclosureSubsequentEventsAdditionalInformation Subsequent Events - Additional Information (Detail) Details 80 false false All Reports Book All Reports In ''Consolidated Balance Sheets'', column(s) 2, 5, 6 are contained in other reports, so were removed by flow through suppression. In ''Consolidated Statements of Cash Flows (Unaudited)'', column(s) 1, 2 are contained in other reports, so were removed by flow through suppression. ozrk-20150630.xml ozrk-20150630_cal.xml ozrk-20150630_def.xml ozrk-20150630_lab.xml ozrk-20150630_pre.xml ozrk-20150630.xsd true true