Cover [Abstract] Entity Central Index Key Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Period Focus Amendment Flag Document Type Document Quarterly Report Document Transition Report Document Period End Date Entity File Number Entity Registrant Name Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Address, Address Line One Entity Address, City or Town Entity Address, State or Province Entity Address, Postal Zip Code City Area Code Local Phone Number Title of 12(b) Security Trading Symbol Name of Exchange on which Security is Registered Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Ex Transition Period Entity Shell Company Entity Common Stock, Shares Outstanding Statement of Financial Position [Abstract] Assets: Cash and cash equivalents Fixed income securities, at fair value Fair Value Available-for-sale Securities, Debt Securities, Estimated Fair Value Total fixed income securities Equity securities, at fair value Total equity securities Other investments Total cash and investments Investments and Cash Premiums and agents' balances receivable Deferred policy acquisition costs Balance, beginning of period Balance, end of period Reinsurance recoverables on losses Income tax recoverable Accrued investment income Property and equipment Total property and equipment, net Deferred income taxes Goodwill and other intangibles Other assets Total assets Total assets Liabilities: Unpaid losses and loss adjustment expenses Unearned premiums Reinsurance premiums payable Reinsurance premiums payable. Deferred income taxes Deferred Income Tax Liabilities, Net Payable to Federal Crop Insurance Corporation Westminster consideration payable Accrued expenses and other liabilities Total liabilities Total liabilities Commitments and contingencies Shareholders' equity: Equity: Common stock, $0.01 par value, authorized: 25,000,000 shares; issued: 23,000,000 shares; and outstanding: 2022 – 21,147,681 shares, 2021 – 21,219,808 shares Preferred stock, without par value, authorized 5,000,000 shares; no shares issued or outstanding Additional paid-in capital Unearned employee stock ownership plan shares Unearned employee ownership plan shares, value. UnearnedEmployeeOwnershipPlanShares Retained earnings Accumulated other comprehensive income (loss), net of income taxes Treasury stock, at cost, 2022 – 1,733,894 shares, 2021 – 1,661,767 shares Treasury Stock, Value Non-controlling interest Total shareholders' equity Balance Balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and shareholders' equity Total liabilities and equity Liabilities and Equity Common stock, par value Common stock, shares authorized Common stock, shares issued Common stock, shares outstanding Preferred stock, shares authorized Preferred stock, shares issued Preferred stock, shares outstanding Treasury stock, shares Income Statement [Abstract] Revenues: Net premiums earned Net premiums Fee and other income Fee and other income (expenses) Net investment income Net investment income (loss) Net investment gains (losses) Net capital gain on investments Net capital gain on investments Total revenues Total revenues Expenses: Losses and loss adjustment expenses Net losses and loss adjustment expenses Net losses and loss adjustment expenses Amortization of deferred policy acquisition costs Other underwriting and general expenses Total expenses Total expenses Income (loss) before income taxes Income (loss) before income taxes Income tax expense (benefit) Net income (loss) Net income (loss) Net Income (loss) Net income (loss) attributable to non-controlling interest Net loss attributable to non-controlling interest Net income (loss) attributable to NI Holdings, Inc. Net income (loss) attributable to NI Holdings, Inc. Earnings (loss) per common share: Basic Diluted Share data: Weighted average common shares outstanding used in basic per common share calculations Plus: Dilutive securities Weighted average common shares used in diluted per common share calculations Statement [Table] Statement, Equity Components [Axis] Equity Components [Axis] Attributable to NI Holdings Inc [Member] Attributable to Non-Controlling Interest [Member] Statement [Line Items] Other comprehensive income (loss), before income taxes: Holding gains (losses) on investments Holding gains/losses on investments. Reclassification adjustment for net realized losses (gains) included in net income (loss) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Other comprehensive income (loss), before income taxes Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent Income tax benefit (expense) related to items of other comprehensive income (loss) Income tax expense related to items of other comprehensive income. States and Political Subdivisions Special Revenue [Member] Other comprehensive income (loss), net of income taxes Other Comprehensive Income (Loss), Net of Tax Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent Common Stock [Member] Common Stock Common stock [Member] Additional Paid-in Capital [Member] Additional Paid-in Capital Unearned Employee Stock Ownership Plan Shares [Member] Unearned Employee Stock Ownership Plan Shares Unearned Employee Stock Ownership Plan Shares [Member] Retained Earnings [Member] Retained Earnings Accumulated Other Comprehensive Income (Loss), Net of Income Taxes [Member] Accumulated Other Comprehensive Income (Loss), Net of Income Taxes Treasury Stock [Member] Treasury Stock Non-Controlling Interest [Member] Non-Controlling Interest Cumulative effect of change in accounting for equity securities Cumulative effect of change in accounting for equity securities. Other comprehensive income (loss), net of income taxes Purchase of treasury stock Treasury Stock, Value, Acquired, Cost Method Share-based compensation Issuance of vested award shares Statement of Cash Flows [Abstract] Cash flows from operating activities: Adjustments to reconcile net income (loss) to net cash flows from operating activities: Net investment losses (gains) Gain (Loss) on Sale of Investments Deferred income tax expense (benefit) Increase (Decrease) in Deferred Income Taxes Depreciation of property and equipment The amount of depreciation or (credit) during the period for property, plant and equipment. Amortization of intangibles Share-based compensation Amortization of deferred policy acquisition costs Amortization of deferred policy acquisition costs Deferred Policy Acquisition Costs, Amortization Expense Deferral of policy acquisition costs Deferral of policy acquisition costs Net amortization of premiums and discounts on investments Accretion (Amortization) of Discounts and Premiums, Investments Loss (gain) on sale of property and equipment Gain (Loss) on Disposition of Property Plant Equipment Changes in operating assets and liabilities: Premiums and agents’ balances receivable Increase (Decrease) in Other Receivables Reinsurance premiums receivable / payable Increase (Decrease) in Reinsurance Recoverable Reinsurance recoverables on losses Reinsurance recoverables on losses. Surplus Notes Two [Member] Accrued investment income Increase (Decrease) in Accrued Investment Income Receivable Federal Crop Insurance Corporation receivable / payable Increase decrease in Reinsurance receivables. Income tax recoverable / payable Increase (Decrease) in Income Taxes Receivable Other assets Increase (Decrease) in Other Operating Assets Unpaid losses and loss adjustment expenses Increase (Decrease) in Liability for Claims and Claims Adjustment Expense Reserve Unearned premiums Increase (Decrease) in Unearned Premiums Accrued expenses and other liabilities Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities Net cash flows from operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Proceeds from maturities and sales of fixed income securities Proceeds from sales of equity securities Purchases of fixed income securities Payments to Acquire Debt Securities, Available-for-Sale Purchases of equity securities Payments to Acquire Equity Securities, FV-NI Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Proceeds from sale of other investments and other Payments for (Proceeds from) Other Investing Activities Net cash flows from investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Purchases of treasury stock Payments for Repurchase of Equity Installment payment on Westminster consideration payable Installment payment on Westminster consideration payable. Northern Plains [Member] Issuance of vested award shares Proceeds from Issuance of Common Stock Net cash flows from financing activities Net Cash Provided by (Used in) Financing Activities Net decrease in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Federal and state income taxes paid Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization Accounting Policies [Abstract] Basis of Presentation and Accounting Policies Marketable Securities [Abstract] Investments [Abstract] Investments Investments, All Other Investments [Abstract] Fair Value Measurements Reinsurance Disclosures [Abstract] Reinsurance Deferred Policy Acquisition Costs Disclosures [Abstract] Deferred Policy Acquisition Costs Liability for Unpaid Claims and Claims Adjustment Expense, Activity in Liability [Abstract] Unpaid Losses and Loss Adjustment Expenses Property, Plant and Equipment [Abstract] Property and Equipment Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Other Intangibles Related Party Transactions [Abstract] Related Party Transactions Compensation Related Costs [Abstract] Benefit Plans Debt Disclosure [Abstract] Line of Credit Income Tax Disclosure [Abstract] Income Taxes Leases, Operating [Abstract] Operating Leases Commitments and Contingencies Disclosure [Abstract] Contingencies