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Income Taxes - Components of Deferred Tax Assets (Liabilities) (Details) Details 88 false false R89.htm 088 - Disclosure - Note 14 - Accumulated Other Comprehensive Income (Loss) - Changes in Accumulated Other Comprehensive Income (Loss) (Details) Sheet http://www.b1bank.com/20191231/role/statement-note-14-accumulated-other-comprehensive-income-loss-changes-in-accumulated-other-comprehensive-income-loss-details Note 14 - Accumulated Other Comprehensive Income (Loss) - Changes in Accumulated Other Comprehensive Income (Loss) (Details) Details http://www.b1bank.com/20191231/role/statement-note-14-accumulated-other-comprehensive-income-loss-tables 89 false false R90.htm 089 - Disclosure - Note 15 - Shareholders' Equity and Regulatory Matters - (Details Textual) Sheet http://www.b1bank.com/20191231/role/statement-note-15-shareholders-equity-and-regulatory-matters-details-textual Note 15 - Shareholders' Equity and Regulatory Matters - (Details Textual) Details http://www.b1bank.com/20191231/role/statement-note-15-shareholders-equity-and-regulatory-matters-tables 90 false false R91.htm 090 - Disclosure - Note 15 - Stockholders' Equity and Regulatory Matters - Actual Capital Amounts and Ratios (Details) Sheet http://www.b1bank.com/20191231/role/statement-note-15-stockholders-equity-and-regulatory-matters-actual-capital-amounts-and-ratios-details Note 15 - Stockholders' Equity and Regulatory Matters - Actual Capital Amounts and Ratios (Details) Details 91 false false R92.htm 091 - Disclosure - Note 16 - Stock Based Compensation - (Details Textual) Sheet http://www.b1bank.com/20191231/role/statement-note-16-stock-based-compensation-details-textual Note 16 - Stock Based Compensation - (Details Textual) Details http://www.b1bank.com/20191231/role/statement-note-16-stock-based-compensation-tables 92 false false R93.htm 092 - Disclosure - Note 16 - Stock Based Compensation - Restricted Stock Award Activity (Details) Sheet http://www.b1bank.com/20191231/role/statement-note-16-stock-based-compensation-restricted-stock-award-activity-details Note 16 - Stock Based Compensation - Restricted Stock Award Activity (Details) Details 93 false false R94.htm 093 - Disclosure - Note 16 - Stock Based Compensation - Summary of Stock Option Activity (Details) Sheet http://www.b1bank.com/20191231/role/statement-note-16-stock-based-compensation-summary-of-stock-option-activity-details Note 16 - Stock Based Compensation - Summary of Stock Option Activity (Details) Details 94 false false R95.htm 094 - Disclosure - Note 17 - Employee Benefit Plans - (Details Textual) Sheet http://www.b1bank.com/20191231/role/statement-note-17-employee-benefit-plans-details-textual Note 17 - Employee Benefit Plans - (Details Textual) Details http://www.b1bank.com/20191231/role/statement-note-17-employee-benefit-plans- 95 false false R96.htm 095 - Disclosure - Note 18 - Other Expenses - Schedule of Other Expenses (Details) Sheet http://www.b1bank.com/20191231/role/statement-note-18-other-expenses-schedule-of-other-expenses-details Note 18 - Other Expenses - Schedule of Other Expenses (Details) Details 96 false false R97.htm 096 - Disclosure - Note 19 - Financial Instruments With Off-balance-sheet Risk - 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