Short Term Debt Disclosure [Abstract] Short Term Debt Disclosure [Abstract] Schedule of Short-term Debt [Table] Schedule of Short-term Debt [Table] Short-term Debt, Type [Axis] Short-term Debt, Type [Axis] Short-term Debt, Type [Domain] Short-term Debt, Type [Domain] Federal Home Loan Bank Advances [Member] Federal Home Loan Bank Advances [Member] Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Domain] Debt Instrument, Redemption, Period [Domain] Debt Instrument, Redemption, Period One [Member] Debt Instrument, Redemption, Period One [Member] Debt Instrument, Redemption, Period Two [Member] Debt Instrument, Redemption, Period Two [Member] Short-term Debt [Line Items] Short-term Debt [Line Items] Short-term Debt Short-term Debt Line of Credit Facility, Interest Rate During Period Line of Credit Facility, Interest Rate During Period Income Statement [Abstract] Statement [Table] Statement [Table] Dividends [Axis] Dividends [Axis] Dividends [Domain] Dividends [Domain] Cash dividend per common share Regular quarterly cash dividend [Member] Regular quarterly cash dividend [Member] Special cash dividend per common share Special cash dividend [Member] Special cash dividend [Member] Statement [Line Items] Statement [Line Items] Revenues: Revenues [Abstract] Interest sensitive product charges Insurance Commissions and Fees Traditional life insurance premiums Premiums Earned, Net, Life Net investment income Net Investment Income Net realized capital gains (losses) Gain (Loss) on Investments, Excluding Other than Temporary Impairments Net other-than-temporary impairment losses recognized in earnings Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net Other income Other Income Total revenues Revenues Benefits and expenses: Benefits, Losses and Expenses [Abstract] Interest sensitive product benefits Interest Sensitive and Index Product Benefits Interest Sensitive and Index Product Benefits, including interest credited to policyholder account balances, index credits, amortization of deferred sales inducements, and death benefits related to interest sensitive products (annuity and universal life). Traditional life insurance benefits Policyholder Benefits and Claims Incurred, Net Policyholder dividends Policyholder Dividends, Expense Underwriting, acquisition and insurance expenses Selling, General and Administrative Expense Interest expense Interest Expense Other expenses Other Cost and Expense, Operating Total benefits and expenses Benefits, Losses and Expenses Income before equity method investments, income taxes and noncontrolling interest Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income taxes Income Tax Expense (Benefit) Equity income, net of related income taxes Income (Loss) from Equity Method Investments Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net loss (income) attributable to noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest Net income attributable to FBL Financial Group, Inc. Net Income (Loss) Attributable to Parent Earnings per common share Earnings Per Share, Basic Earnings per common share - assuming dilution Earnings Per Share, Diluted Cash dividends per common share Common Stock, Dividends, Per Share, Cash Paid Statement of Stockholders' Equity [Abstract] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2016-01 [Member] Accounting Standards Update 2016-01 [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Series B Preferred Stock Preferred Stock [Member] Class A and Class B Common Stock Common Stock [Member] Accumulated Other Comprehensive Income AOCI Attributable to Parent [Member] Retained Earnings Retained Earnings [Member] Non- controlling Interest Noncontrolling Interest [Member] Balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets Net income Other comprehensive income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Issuance of common stock under compensation plans Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Purchase of common stock Stock Repurchased During Period, Value Dividends on preferred stock Dividends, Preferred Stock, Cash Dividends on common stock Dividends, Common Stock, Cash Receipts related in noncontrolling interest Noncontrolling Interest, Period Increase (Decrease) Balance Income Tax Disclosure [Abstract] Significant Accounting Policies [Abstract] Significant Accounting Policies [Abstract] Significant Accounting Policies Significant Accounting Policies [Text Block] Earnings Per Share [Abstract] Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Stockholders' Equity Attributable to Parent [Abstract] Other Comprehensive Income Location [Axis] Other Comprehensive Income Location [Axis] Other Comprehensive Income Location [Domain] Other Comprehensive Income Location [Domain] reclassifications out of accumulated other comprehensive income [Member] reclassifications out of accumulated other comprehensive income [Member] Reclassifications out of accumulated other comprehensive income [Member] Accumulated Net Unrealized Investment Gain (Loss) [Member] Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Accumulated Other-than-Temporary Impairment [Member] Accumulated Other-than-Temporary Impairment Attributable to Parent [Member] Accumulated Defined Benefit Plans Adjustment [Member] Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Reclassification Adjustments, Net of Tax Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Reclassification Adjustments, Net of Tax Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Reclassification Adjustments, Net of Tax Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, after Tax Other Comprehensive Income (Loss), Reclassification Adjustment for Sale of Securities Included in Net Income, Net of Tax Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, Net of Tax Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax Investment Operations [Abstract] Investment Operations [Abstract] Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Credit Quality Indicator [Axis] Internal Credit Assessment [Axis] Financing Receivable, by Credit Quality Indicator [Domain] Internal Credit Assessment [Domain] Financing Receivable, Impaired [Line Items] Financing Receivable, Impaired [Line Items] Impaired Financing Receivable, Unpaid Principal Balance Impaired Financing Receivable, Unpaid Principal Balance Financing Receivable, Allowance for Credit Losses Financing Receivable, Allowance for Credit Losses Impaired Financing Receivable, Recorded Investment Impaired Financing Receivable, Recorded Investment Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Other Investments [Member] Other Investments [Member] Reinsurance Recoverable Including Reinsurance Premium Paid [Member] Reinsurance Recoverable Including Reinsurance Premium Paid [Member] Available-for-sale Securities [Member] Available-for-sale Securities [Member] Contract Holder Funds [Member] Contract Holder Funds [Member] Other Liabilities [Member] Other Liabilities [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Investment Income [Member] Investment Income [Member] Insurance sensitive product charges [Member] Insurance sensitive product charges [Member] Insurance sensitive product charges [Member] Derivative Instrument Risk [Axis] Derivative Instrument [Axis] Derivative Contract Type [Domain] Derivative Contract [Domain] Equity Option [Member] Equity Option [Member] Embedded Derivative Financial Instruments - MODCO [Member] Embedded Derivative Financial Instruments - MODCO [Member] Embedded Derivative Financial Instruments - MODCO [Member] Embedded Derivative Financial Instruments - Interest only Security [Member] Embedded Derivative Financial Instruments - Interest only Security [Member] Embedded Derivative Financial Instruments - Interest only Security [Member] Embedded Derivative Financial Instruments [Member] Embedded Derivative Financial Instruments [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Derivative assets Derivative Asset Derivative Liabilities Derivative Liability Derivative, Gain (Loss) on Derivative, Net Derivative, Gain (Loss) on Derivative, Net Fair Value Disclosure, Off-balance Sheet Risks, Amount, Asset Fair Value Disclosure, Off-balance Sheet Risks, Amount, Asset Net Derivative Exposure Net Derivative Exposure Net Derivative Exposure Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] Major Types of Debt and Equity Securities [Domain] Corporate Securities Corporate Debt Securities [Member] Residential mortgage-backed securities [Member] Residential Mortgage Backed Securities [Member] Commercial mortgage-backed securities [Member] Commercial Mortgage Backed Securities [Member] Other asset backed securities [Member] Asset-backed Securities, Securitized Loans and Receivables [Member] United States Government and agencies US Treasury and Government [Member] State, municipal and other government [Member] US States and Political Subdivisions Debt Securities [Member] Debt Securities [Member] Debt Securities [Member] Non-redeemable preferred stock [Member] Nonredeemable Preferred Stock [Member] Common Stock Equity Securities [Member] Equity Securities [Member] Commercial mortgage-backed Mortgage-backed Securities, Issued by Private Enterprises [Member] Schedule of Available-for-sale Securities [Line Items] Schedule of Available-for-sale Securities [Line Items] Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss percent of total percent of total Percent of total fixed maturities Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions Available For Sale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Issuers Available For Sale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Issuers Available For Sale Securities In Unrealized Loss Positions Qualitative Disclosure Number Of Issuers Available for sale Securities Continuous Unrealized Loss Position Maximum Loss by issuer Available for sale Securities Continuous Unrealized Loss Position Maximum Loss by issuer Available for sale Securities Continuous Unrealized Loss Position Maximum Loss by issuer Corporate Hybrid preferred securities [Member] Other Debt Obligations [Member] Redeemable Preferred Stock [Member] Redeemable Preferred Stock [Member] Amortized Cost Available-for-sale Securities, Amortized Cost Basis Available-for-sale Securities, Debt Maturities, Amortized Cost Basis Available-for-sale Debt Securities, Amortized Cost Basis Available-for-sale Equity Securities, Amortized Cost Basis Available-for-sale Equity Securities, Amortized Cost Basis Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax Available-for-sale Equity Securities, Accumulated Gross Unrealized Loss, before Tax Available-for-sale Equity Securities, Accumulated Gross Unrealized Loss, before Tax Available-for-sale Securities Available-for-sale Securities Available-for-sale Securities, Equity Securities Available-for-sale Securities, Equity Securities Non-credit losses on other-than-temporary impairments Other than Temporary Impairment Losses, Investments Portion in Other Comprehensive Income, Before Tax, Including Portion Attributable to Noncontrolling Interest, Available-for-sale Securities The amount of other than temporary impairment loss on an available-for-sale debt security related to factors other than credit losses when the entity does not intend to sell the security and it is not more likely than not that the entity will be required to sell the security before recovery of its amortized cost basis. This amount, which includes the portion attributable to the noncontrolling interest, if any, is a portion of the deduction from the total impairment losses of investments (before taxes) presented on the income statement; this amount is also referred to as the amount incurred by the reporting entity or the consolidated entity. Stockholders' Equity Note [Abstract] Schedule of Stock by Class [Table Text Block] Schedule of Stock by Class [Table Text Block] Schedule of Comprehensive Income (Loss) [Table Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Disclosure of Reclassification Amount [Text Block] Disclosure of Reclassification Amount [Text Block] Other [Abstract] Other [Abstract] Summary of Investment Holdings [Table] Summary of Investment Holdings [Table] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Affordable Housing Tax Credit Investments Affordable Housing Tax Credit Investments [Member] Affordable Housing Tax Credit Investments [Member] Summary of Investment Holdings [Line Items] Summary of Investment Holdings [Line Items] Other Commitment Other Commitment Other Commitment, Due in Next Twelve Months Other Commitment, Due in Next Twelve Months Other Commitment, Due in Second Year Other Commitment, Due in Second Year Other Commitment, Due in Third Year Other Commitment, Due in Third Year Qualified Affordable Housing Project Investments, Commitment Qualified Affordable Housing Project Investments, Commitment Available-for-sale Securities, Debt Maturities [Abstract] Available-for-sale Securities, Debt Maturities [Abstract] Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract] Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract] Due in one year or less, amortized cost basis Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis Due after one year through five years, amortized cost basis Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis Due after five years through ten years, amortized cost basis Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Amortized Cost Basis Due after ten years, amortized cost basis Available-for-sale Securities, Debt Maturities, after Ten Years, Amortized Cost Basis Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis Mortgage-backed and other asset-backed, amortized cost basis Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Amortized Cost Basis Total fixed maturities, amortized cost basis Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract] Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract] Due in one year or less, fair value Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value Due after one year through five years, fair value Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value Due after five years through ten years, fair value Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value Due after ten years, fair value Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value Total fixed maturities with maturity date, fair value Available-for-sale Securities, Debt Maturities, Single Maturity Date Mortgage-backed and other asset-backed, fair value Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value Total fixed maturities, fair value Available-for-sale Securities, Debt Securities Fair Values [Abstract] Fair Values [Abstract] Fair Value Fair Value Disclosures [Text Block] Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Table] Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Recurring [Member] Fair Value, Measurements, Recurring [Member] Asset Class [Axis] Asset Class [Axis] Fair Value by Asset Class [Domain] Asset Class [Domain] Asset fair value by technique [Member] Asset fair value by technique [Member] Asset fair value by technique - level 3 assets not including those for which fair value was based on non-binding broker quotes where we could not reasonably obtain the quantitative unobservable inputs. [Member] Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Index Annuity Embedded Derivatives [Member] Index Annuity Embedded Derivatives [Member] Index Annuity Embedded Derivatives included in future policy benefits [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items] Assets, Fair Value Disclosure Assets, Fair Value Disclosure Future policy benefits - index annuity embedded derivatives Liabilities Related to Investment Contracts, Fair Value Disclosure Fair Value Measurements, Valuation Techniques Fair Value Measurements, Valuation Techniques Fair Value Measurements, Significant Assumptions Fair Value Measurements, Significant Assumptions Input range and weighted average Input range and weighted average Input range and weighted average of unobservable inputes to fair value measurements Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Equity Method Investments and Joint Ventures [Abstract] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net Pre-Tax on Equity Income (Loss) Pre-Tax on Equity Income (Loss) Pre-Tax on Equity Income (Loss) Equity Method Investments Equity Method Investments Income (Loss) from Affordable Housing Projects, Equity Method Investments Income (Loss) from Affordable Housing Projects, Equity Method Investments Tax impact of Income from Equity Method Investments Tax impact of Income from Equity Method Investments Tax impact of Income from Equity Method Investments - This item represents the tax on the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. Investment Tax Credit Investment Tax Credit Income (Loss) from Equity Method Investments Segment Information [Abstract] Segment Information [Abstract] Reconciliation of Other Significant Reconciling Items from Segments to Consolidated [Table] Reconciliation of Other Significant Reconciling Items from Segments to Consolidated [Table] Business Segments [Axis] Segments [Axis] Segment [Domain] Segments [Domain] Life Insurance Segment Life Insurance Product Line [Member] Life insurance - interest sensitive Life insurance - interest sensitive [Member] Life insurance - interest sensitive [Member] Life insurance - traditional Life insurance - traditional [Member] Life insurance - traditional [Member] Annuity Segment Annuity Segment [Member] Annuity Segment [Member] Corporate and Other Corporate and Other [Member] Policy charges [Axis] Policy charges [Axis] Policy charges - detail by type of charge [Axis] Policy Charges [Domain] Policy Charges [Domain] Policy Charges [Domain] Cost of insurance charges & Surrender charges Cost of insurance charges & Surrender charges [Member] Cost of insurance charges & Surrender charges [Member] Admin charges Admiin charges [Member] Admiin charges [Member] Cost of insurance charges Cost of insurance charges [Member] Cost of insurance charges [Member] Surrender charges Surrender charges [Member] Surrender charges [Member] Separate account charges Separate account charges [Member] Separate account charges [Member] Amortization of policy initiation fees Amortization of policy initiation fees [Member] Amortization of policy initiation fees for bonus premiums or bonus interest that was deferred upon policy initiation. [Member] Segment Reporting, Other Significant Reconciling Item [Line Items] Segment Reporting, Other Significant Reconciling Item [Line Items] Premiums collected Proceeds from Insurance Premiums Collected Change in due premiums and other Increase (Decrease) in Premiums Receivable Statement of Cash Flows [Abstract] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Operating activities Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Interest credited to account balances Interest Credited to Policy Owner Account Charges for mortality, surrenders and administration Charges for mortality surrenders and administration Charges to policyholder deposits which reduce future policy benefits but are recorded as earnings for the period. Net realized (gains) losses on investments Realized Investment Gains (Losses) Change in fair value of derivatives Unrealized Gain (Loss) on Derivatives Increase in liabilities for life insurance and other future policy benefits Increase (Decrease) in Life Insurance Liabilities Deferral of acquisition costs Increase (Decrease) in Deferred Policy Acquisition Costs Amortization of deferred acquisition costs and value of insurance in force Amortization of Other Deferred Charges Change in reinsurance recoverable Increase (Decrease) in Reinsurance Recoverable Provision for deferred income taxes Deferred Income Tax Expense (Benefit) Other Other Noncash Income (Expense) Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Investing activities Net Cash Provided by (Used in) Investing Activities [Abstract] Sales, maturities or repayments: Proceeds from Sale, Maturity and Collection of Investments [Abstract] Fixed maturities - available for sale Proceeds from sale, maturity or repayments of Available-for-sale Securities, Debt The cash inflow associated with the sale, maturities (principal being due), prepayments and calls (requests of early payments) on debt securities classified as available-for-sale securities. Equity securities - available for sale Proceeds from Sale of Available-for-sale Securities, Equity Mortgage loans Proceeds from Sale and Collection of Mortgage Notes Receivable Derivative instruments Proceeds from Derivative Instrument, Investing Activities Policy loans Proceeds from Collection of Policy Loans Securities and indebtedness of related parties Proceeds from Sale of Equity Method Investments Real Estate Proceeds from Sale of Real Estate Held-for-investment Other long-term investments Proceeds from Sale and Maturity of Other Investments Acquisitions: Payments to Acquire Investments [Abstract] Fixed maturities - available for sale Payments to Acquire Available-for-sale Securities, Debt Equity securities - available for sale Payments to Acquire Available-for-sale Securities, Equity Mortgage loans Payments to Acquire Mortgage Notes Receivable Derivative instruments Payments for Derivative Instrument, Investing Activities Policy loans Payments to Fund Policy Loans Securities and indebtedness of related parties Payments to Acquire Equity Method Investments Other long-term investments Payments to Acquire Other Investments Short-term investments, net change Payments for (Proceeds from) Short-term Investments Purchases and disposals of property and equipment, net Payments for (Proceeds from) Productive Assets Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Financing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Contract holder account deposits Additions to Contract Holders Funds Contract holder account withdrawals Withdrawal from Contract Holders Funds Dividends paid Payments of Ordinary Dividends, Common Stock Proceeds from Short-term Debt Proceeds from Short-term Debt Issuance or repurchase of common stock, net Proceeds from (Repurchase of) Equity Proceeds from (Payments for) Other Financing Activities Proceeds from (Payments for) Other Financing Activities Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents at beginning of period Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents at end of period Supplemental disclosures of cash flow information Supplemental Cash Flow Information [Abstract] Cash paid during the period for interest Interest Paid Cash (paid) received during the period for income taxes Income Taxes Paid, Net Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Net income attributable to FBL Financial Group, Inc. LIHTC equity losses related to the enactment of the Tax Act LIHTC equity losses related to the enactment of the Tax Act LIHTC equity losses related to the enactment of the Tax Act Realized gains/losses on investments (1) Realized gains losses on investments net of offsets Realized gains losses on investments net of offsets, not included in operating income as they can fluctuate greatly from quarter to quarter. Change in net unrealized gains/losses on derivatives Derivatives unrealized gain net of offsets Derivatives change in net unrealized gain net of offsets, reconciling item from net income to operating income due to fluctuations from quarter to quarter. Operating Income (Loss) Operating Income (Loss) Pre-Tax Operating Income (Loss) Pre-Tax Operating Income (Loss) Pre-Tax Operating Income (Loss) Income tax on operating income Income tax on operating income Income tax on operating income Operating revenues Operating revenues Operating revenues, not net of expenses. Net realized gains (losses) on investments (1) Realized gains on investments related to revenue Realized gains on investments, including only the offset for unearned revenue reserve as other offsets do not impact revenue. Change in net unrealized gains/losses on derivatives (1) Derivative unrealized related to revenues Derivative change in net unrealized related to revenues. Adjustment between Net income and Operating income. Includes only items included in revenues. Consolidated revenues Income Tax on Equity Income Income Tax on Equity Income Income Tax on Equity Income Equity Income (Loss), net of related taxes, included in NON-GAAP operating income Equity Income (Loss), net of related taxes, included in NON-GAAP operating income Equity Income (Loss), net of related taxes, included in NON-GAAP operating income Schedule of Financial Instruments Not Reported at Fair Value [Table] Schedule of Financial Instruments Not Reported at Fair Value [Table] Schedule of Financial Instruments Not Reported at Fair Value [Table] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Portion at Other than Fair Value Measurement [Member] Portion at Other than Fair Value Measurement [Member] Reported Value Measurement [Member] Reported Value Measurement [Member] Financial Instruments Not Reported at Fair Value [Line Items] Financial Instruments Not Reported at Fair Value [Line Items] Financial Instruments Not Reported at Fair Value [Line Items] Mortgage Loans on Real Estate, Commercial and Consumer, Net Mortgage Loans on Real Estate, Commercial and Consumer, Net Policy loans Loans, Gross, Insurance Policy Other investments Total assets Assets not measured at fair value Assets not measured at fair value Future policy benefits Supplemental contracts without life contingencies Supplemental contracts without life contingencies, fair value disclosure Supplemental contracts without life contingencies, fair value disclosure Deposit Contracts, Liabilities Deposit Contracts, Liabilities Advance premiums and other deposits Advance premiums and other deposits, fair value disclosure Advance premiums and other deposits, fair value disclosure Short term debt, fair value disclosure Short term debt, fair value disclosure Short term debt, fair value disclosure Long-term debt Long-term Debt, Fair Value Liabilities related to separate accounts Separate Accounts, Liability Total liabilities Liabilities not measured at fair value Liabilities not measured at fair value Defined Benefit Plan [Abstract] Defined Benefit Plan [Abstract] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Pension Plan [Member] Pension Plan [Member] Other Pension Plan [Member] Other Pension Plan [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Expected return on assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Amortization of prior service cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Amortization of actuarial loss Defined Benefit Plan, Amortization of Gain (Loss) Net periodic pension cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) FBL Financial Group, Inc. share of net periodic pension costs Net periodic pension cost individual entity share Net periodic pension cost individual entity share. Mortgage Loans on Real Estate Schedule [Table] Mortgage Loans on Real Estate Schedule [Table] Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Real Estate, Property Type [Domain] Real Estate [Domain] Office [Member] Office Building [Member] Retail [Member] Retail Site [Member] Industrial [Member] Industrial Property [Member] Other property type [Member] Other Property [Member] Investment by Geographic Area [Axis] Investment Geographic Region [Axis] Investment Geographic Region [Domain] Investment Geographic Region [Domain] South Atlantic [Member] South Atlantic [Member] Represents the South Atlantic region of the United States. Pacific [Member] Pacific [Member] Represents the Pacific region of the United States. West North Central [Member] West North Central [Member] Represents the West North Central region of the United States. Mountain [Member] Mountain [Member] Represents the Mountain region of the United States. East North Central [Member] East North Central [Member] Represents the East North Central region of the United States. West South Central [Member] West South Central [Member] Represents the West South Central region of the United States. East South Central [Member] East South Central [Member] East South Central [Member] New England [Member] New England [Member] New England [Member] Middle Atlantic [Member] Middle Atlantic [Member] Middle Atlantic [Member] Loan-to-Value Ratio [Axis] Loan-to-Value Ratio [Axis] Loan-to-Value Ratio for mortgage loan credit quality [Axis] Total loan-to-value [Domain] Total loan-to-value [Domain] Total loan-to-value [Domain] 0% to 50% loan to value [Member] 0% to 50% loan to value [Member] 0% to 50% loan-to-value ratio [Member] 51% to 60% loan-to-value [Member] 51% to 60% loan-to-value [Member] 51% to 60% loan-to-value ratio [Member] 61% to 70% loan-to-value [Member] 61% to 70% loan-to-value [Member] 61% to 70% loan-to-value ratio [Member] 71% to 80% loan-to-value [Member] 71% to 80% loan-to-value [Member] 71% to 80% loan-to-value ratio [Member] 81% to 90% loan to value [Member] 81% to 90% loan to value [Member] 81% to 90% loan to value ratio [Member] MortgageLoans by Year of Origination [Axis] MortgageLoans by Year of Origination [Axis] MortgageLoans by Year of Origination [Axis] Mortgage Loans by Year of Origination [Domain] Mortgage Loans by Year of Origination [Domain] Mortgage Loans by Year of Origination [Domain] Year of origination 2018 [Member] Year of origination 2018 [Member] Year of origination 2018 [Member] Year of origination 2017 [Member] Year of origination 2017 [Member] Year of origination 2017 [Member] Year of origination 2016 [Member] Year of origination 2016 [Member] Year of origination 2016 [Member] Year of origination 2015 [Member] Year of origination 2015 [Member] Year of origination 2015 Year of origination 2014 [Member] Year of origination 2014 [Member] Year of origination 2014 [Member] Year of origination prior [Member] Year of origination prior [Member] Year of origination prior [Member] Mortgage Loans on Real Estate [Line Items] Mortgage Loans on Real Estate [Line Items] Contractual Obligation Contractual Obligation Mortgage Loans on Real Estate, Carrying Amount of Mortgages Mortgage Loans on Real Estate, Carrying Amount of Mortgages Percentage of Mortgage Loans Percentage of Mortgage Loans Represents amount as a percentage of the total amortized cost of mortgage loans. Schedule of Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table] Schedule of Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table] Debt Security [Axis] Debt Security [Axis] Major Types of Debt Securities [Domain] Major Types of Debt Securities [Domain] Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items] Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items] Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward] Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward] Balance at beginning of period Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held Reductions due to securities sold Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Change in Status Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Change in Status Balance at end of period Schedule of Net Benefit Costs [Table Text Block] Schedule of Net Benefit Costs [Table Text Block] Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table] Schedule of Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Table] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items] Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items] Numerator [Abstract] Numerator [Abstract] Numerator [Abstract] Less: Dividends Series B preferred stock Income available to common stockholders Net Income (Loss) Available to Common Stockholders, Basic Denominator [Abstract] Denominator [Abstract] Denominator [Abstract] Weighted average shares - diluted Weighted Average Number of Shares Outstanding, Diluted Weighted average shares - basic Weighted Average Number of Shares Outstanding, Basic Effect of dilutive securities - stock-based compensation Weighted Average Number Diluted Shares Outstanding Adjustment Available-for-sale Securities [Table Text Block] Available-for-sale Securities [Table Text Block] Investments Classified by Contractual Maturity Date [Table Text Block] Investments Classified by Contractual Maturity Date [Table Text Block] Unrealized Gain (Loss) on Investments [Table Text Block] Unrealized Gain (Loss) on Investments [Table Text Block] Schedule of Unrealized Loss on Investments [Table Text Block] Schedule of Unrealized Loss on Investments [Table Text Block] Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table Text Block] Other than Temporary Impairment, Credit Losses Recognized in Earnings [Table Text Block] Realized Gain (Loss) on Investments [Table Text Block] Realized Gain (Loss) on Investments [Table Text Block] Mortgage Loans by Colateral Type [Table Text Block] Mortgage Loans by Colateral Type [Table Text Block] Mortgage Loans by Colateral Type [Table Text Block] Mortgage Loans by Geograpic Location [Table Text Block] Mortgage Loans by Geograpic Location [Table Text Block] Mortgage Loans by Geograpic Location [Table Text Block] Mortgage Loans by loan to value ratio [Table Text Block] Mortgage Loans by loan to value ratio [Table Text Block] Mortgage Loans by loan to value ratio [Table Text Block] Mortgage loans by year of origination [Table Text Block] Mortgage loans by year of origination [Table Text Block] Mortgage loans by year of origination [Table Text Block] Impaired Financing Receivables [Table Text Block] Impaired Financing Receivables [Table Text Block] Allowance for Credit Losses on Financing Receivables [Table Text Block] Allowance for Credit Losses on Financing Receivables [Table Text Block] Affordable Housing Program [Text Block] Affordable Housing Program [Text Block] Schedule of Variable Interest Entities [Table Text Block] Schedule of Variable Interest Entities [Table Text Block] Schedule of Derivative Instruments [Table Text Block] Schedule of Derivative Instruments [Table Text Block] Recent Accounting Pronouncements [Abstract] Recent Accounting Pronouncements [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Adjustments for Change in Accounting Principle [Axis] Adjustments for Change in Accounting Principle [Axis] Adjustments for Change in Accounting Principle [Domain] Adjustments for Change in Accounting Principle [Domain] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Basic Earnings Per Share New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Basic Earnings Per Share New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Diluted Earnings Per Share New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Diluted Earnings Per Share Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Asset Balance, beginning of period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Disposals Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Realized and unrealized gains (losses), net, included in net income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Realized and unrealized gains (losses), net, included in other comprehensive income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Transfers Into Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 Transfers out of Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 Amortization included in net income Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset, Amortization Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset, Amortization Asset Balance, end of period Liability balance, beginning of period Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements Realized and unrealized gains (losses), net, included in net income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings Realized and unrealized gains (losses), net, included in other comprehensive income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss) Transfers Into Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers Into Level 3 Transfers out of Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3 Liability balance, end of period Segment Information Segment Reporting Disclosure [Text Block] Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block] Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block] Reconciliation of Revenue from Segments to Consolidated [Table Text Block] Reconciliation of Revenue from Segments to Consolidated [Table Text Block] Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of Segment Reporting Information, by Segment [Table Text Block] Reconciliation of Non-GAAP measures [Table Text Block] Reconciliation of non-GAAP measures [table text block] [Table Text Block] Reconciliation of non-GAAP measures used to my management to evaluate segment performance to corresponding line items in our GAAP financial statements [Table Text Block] Income Tax Income Tax Disclosure [Text Block] Schedule of Gain (Loss) on Investments [Table] Schedule of Gain (Loss) on Investments [Table] Impairments by type [Axis] Impairments by type [Axis] Impairments by type [Axis] Total impairments on investments [Domain] Total impairments on investments [Domain] Total impairments on investments [Domain] Other credit-related [Member] Other credit related impairments [Member] Amount represents credit-related losses for mortgage loans, real estate and fixed maturities written down to fair value. Investments by Category [Axis] Investments by Category [Axis] Gain (Loss) on Investments, Including Marketable Securities and Investments Held at Cost, Categories of Investments [Domain] Marketable Securities and Investments Held at Cost [Domain] Categories of Investments, Marketable Securities, Available-for-sale Securities [Member] Cost-method Investments [Member] Cost-method Investments [Member] Gain (Loss) on Investments [Line Items] Gain (Loss) on Investments [Line Items] Gross gains - fixed maturities - available for sale Available-for-sale Securities, Gross Realized Gains Gross losses - fixed maturities - available for sale Available-for-sale Securities, Gross Realized Losses Realized Gain (Loss) on sales of Equity Securities Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments Realized Gain (Loss) on Disposition of Other Financial Assets Gain (Loss) on Disposition of Other Financial Assets Realized Gain (Loss) on Sales of Other Real Estate Gains (Losses) on Sales of Other Real Estate Realized Gains (Loss) on sales of investments Realized gains (losses) on sales of investments Realized gains (losses) on sales of investments New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Operating Results Net realized capital gains on sales of investments Net impairment loss recognized in earnings Realized gains (losses) on investments recorded in income Gain (Loss) on Investments Proceeds from Sale of Available-for-sale Securities Proceeds from Sale of Available-for-sale Securities, Debt Stockholders' Equity Note Stockholders' Equity Note Disclosure [Text Block] Debt Disclosure [Abstract] Debt Disclosure Debt Disclosure [Text Block] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Common Class A Common Class A [Member] Common Class B Common Class B [Member] Class of Stock [Line Items] Class of Stock [Line Items] Stock Repurchase Program, Remaining Authorized Repurchase Amount Stock Repurchase Program, Remaining Authorized Repurchase Amount Common Stock Special Dividends Per Share Cash Paid Common Stock Special Dividends Per Share Cash Paid Special cash dividends paid during the period for each share of common stock outstanding. Payment Of Special Cash Dividend Payment Of Special Cash Dividend Payment Of Special Cash Dividend Common Stock, Shares, Outstanding Common Stock, Shares, Outstanding Common stock, without par value Common Stock, Value, Outstanding Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Stock Repurchased During Period, Shares Stock Repurchased During Period, Shares Stock Repurchased During Period, Value Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] Variable Interest Entities [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Low income housing tax credits [Member] Low income housing tax credits [Member] Investments in low income housing tax credits, as part of our equity method investments [Member] Investment companies [Member] Investment companies [Member] Investment in investment companies, as part of our equity method investments. Real estate limited partnerships [Member] Real estate limited partnerships [Member] Investments in real estate limited partnerships, as part of our equity method investments [Member] Other VIE investments [Member] Other VIE investments [Member] Investments in other VIE investments, as part of our equity method investments [Member] Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets Variable Interest Entity, Nonconsolidated, Carrying Amount, Assets Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount Estimate of Fair Value Measurement [Member] Estimate of Fair Value Measurement [Member] Fair Value, Valuation Source [Axis] Fair Value, Valuation Source [Axis] Fair Value, Valuation Source [Axis] Valuation Source [Domain] Valuation Source [Domain] Valuation Source [Domain] Third-party vendors [Member] Third-party Vendor [Member] Third-party Vendor valuation source [Member] Priced internally [Member] Internally priced [Member] Internally priced valuation source [Member] Collateralized Debt Obligations [Member] Collateralized Debt Obligations [Member] Defined Benefit Plan Pension and Other Postretirement Benefits Disclosure [Text Block] Investment Operations Investment [Text Block] Statement of Comprehensive Income [Abstract] Change in net unrealized investment gains/losses Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Change in underfunded status of postretirement benefit plans Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Total other comprehensive income (loss), net of tax Total comprehensive income (loss), net of tax Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive (income) loss attributable to noncontrolling interest Total comprehensive income (loss) applicable to FBL Financial Group, Inc. Comprehensive Income (Loss), Net of Tax, Attributable to Parent 10. Segment Information [Abstract] 10. Segment Information [Abstract] Schedule of Indefinite-Lived Intangible Assets [Table] Schedule of Indefinite-Lived Intangible Assets [Table] Indefinite-lived Intangible Assets [Line Items] Indefinite-lived Intangible Assets [Line Items] Goodwill Goodwill Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] Private Equity Funds, Domestic [Member] Private Equity Funds, Domestic [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Mortgage-backed securities available-for-sale Mortgage-backed Securities Available-for-sale, Fair Value Disclosure Cash and short-term investments Cash and short-term investments, fair value disclosure Cash and short-term investments, fair value disclosure Reinsurance recoverable Embedded Derivative, Fair Value of Embedded Derivative Asset Assets held in separate accounts Separate Account Assets Other liabilities Other Liabilities, Fair Value Disclosure Total liabilities Financial and Nonfinancial Liabilities, Fair Value Disclosure Investments Net Asset Value Investments Net Asset Value Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments Statement of Financial Position [Abstract] Preferred Stock Class A common stock, without par value - authorized 88,500,000 shares, issued and outstanding 24,806,796 shares in 2018 and 24,919,113 shares in 2017 Class B common stock, without par value - authorized 1,500,000 shares, issued and outstanding 11,413 shares in 2018 and 2017 Assets Assets [Abstract] Investments: Investments [Abstract] Fixed maturities - available for sale, at fair value (amortized cost: 2018 - $6,922,505; 2017 - $6,757,250) Equity securities at fair value (cost: 2018 - $99,279; 2017 - $96,715) Mortgage loans Real estate Real Estate Investments, Net Short-term investments Short-term Investments Other investments Other Investments Total investments Investments Cash and cash equivalents Securities and indebtedness of related parties Accrued investment income Accrued Investment Income Receivable Amounts receivable from affiliates Accounts Receivable, Related Parties, Current Reinsurance recoverable Reinsurance Recoverables, Including Reinsurance Premium Paid Deferred acquisition costs Deferred Policy Acquisition Costs Value of insurance in force acquired Present Value of Future Insurance Profits, Net Current income taxes recoverable Income Taxes Receivable, Current Other assets Other Assets Total assets Assets Liabilities and stockholders' equity Liabilities and Equity [Abstract] Liabilities: Liabilities [Abstract] Policy liabilities and accruals: Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract] Future policy benefits: Liability for Future Policy Benefits [Abstract] Interest sensitive products Interest sensitive products The accrued obligation to policyholders at the balance sheet date that relates to universal life and variable universal life insurance policies; individual and group annuities (including fixed rate, index and variable); and supplemental contracts involving life contingencies. Traditional life insurance and accident and health products Liability for Future Policy Benefits, Life Other policy claims and benefits Other policy claims and benefits Amounts payable for death benefits net of reinsurance. Also includes an unearned revenue reserve that relect the unamortized balance of charges assessed to interest sensitive contracts to compensate us for services to be performed over future periods. Supplementary contracts without life contingencies Advance premiums and other deposits Other Policyholder Funds Amounts payable to affiliates Accounts Payable, Related Parties, Current Short-term Debt payable to non-affiliates Long-term debt payable to non-affiliates Long-term Debt Current income taxes payable Accrued Income Taxes, Current Deferred income taxes Deferred Tax Liabilities, Net Other liabilities Other Liabilities Total liabilities Liabilities Stockholders' equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] FBL Financial Group, Inc. stockholders' equity: Preferred stock, without par value, at liquidation value - authorized 10,000,000 shares, issued and outstanding 5,000,000 Series B shares Preferred Stock, Value, Outstanding Retained earnings Retained Earnings (Accumulated Deficit) Total FBL Financial Group, Inc. stockholders’ equity Stockholders' Equity Attributable to Parent Noncontrolling interest Stockholders' Equity Attributable to Noncontrolling Interest Total stockholders’ equity Total liabilities and stockholders’ equity Liabilities and Equity Document and Entity Information [Abstract] Document and Entity Information [Abstract] Document Information [Table] Document Information [Table] Document Information, Document [Axis] Document Information, Document [Axis] Document [Domain] Document [Domain] Document Information [Line Items] Document Information [Line Items] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Public Float Entity Public Float Change in offsets to unrealized on investments Change in offsets to unrealized on investments Change in offsets to unrealized on investments, includes changes in amortization pattern of DAC, VIIF & URR and provision for deferred income tax. Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax Income taxes Consolidated Balance Sheets [Abstract] Consolidated Balance Sheets [Abstract] Preferred Stock, Shares Authorized Preferred Stock, Shares Authorized Preferred Stock, Shares Issued Preferred Stock, Shares Issued Preferred Stock, Shares Outstanding Preferred Stock, Shares Outstanding Common Stock, Shares Authorized Common Stock, Shares Authorized Common Stock, Shares, Issued Common Stock, Shares, Issued Net Unrealized Gains Losses [Table] Net Unrealized Gains/Losses with offsets [Table] Accumulated Net Unrealized Investment Gain (Loss) [Member] Accumulated net unrealized investment gain AND OTTI [Member] Accumulated net unrealized investment gain AND OTTI [Member] Net Unrealized Gains Losses [Line Items] Net Unrealized Gains Losses [Line Items] Net Unrealized Gains Losses on investments in accumulated other comprehensive income. Includes adjustmetns for assumed changes in amortization patterns and provision for taxes. [Line Items] Unrealized appreciation on fixed maturities available for sale Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax Assumed changes in amortization of DAC Assumed changes in amortization of DAC Adjustment for assumed changes in amortization of DAC on net unrealized appreciation/depreciation on investments Assumed changes in amortization pattern of VIIF Assumed changes in amortization patter of VIIF Adjustment for assumed changes in amortization of VIIF on net unrealized appreciation/depreciation on investments Assumed changes in amortization pattern of URR Assumed changes in amortization patter of URR Adjustment for assumed changes in amortization of Unearned Revenue Reserves on net unrealized appreciation/depreciation on investments Assumed change in policyholder liability Assumed changes in policyholder liability Assumed changes in policyholder liability Provision for deferred income taxes Provision Deferred Income Tax Benefits, Expense This item represents the applicable deferred income tax impacts of cumulative net unrealized gains/losses on fixed maturities available-for-sale, equity securities available-for-sale and derivative instruments net of adjustments related deferred policy acquisition costs, sales inducements, value of insurance inforce and unearned revenue reserves. Valuation of our Financial Instruments Measured on Recurring Basis by hierarchy levels [Table Text Block] Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Level 3 fixed maturities on Measurement on Recurring Basis by Valuation Technique [Table Text Block] Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Table Text Block] Quantitative Information about Level 3 Fair Value Measurement Inputs [Text Block] Fair Value, Measurement Inputs, Disclosure [Text Block] Level 3 Financial Instruments Changes in Fair Value [Table Text Block] Level 3 Financial Instruments Changes in Fair Value [Table Text Block] Level 3 Financial Instruments Changes in Fair Value, rollforward of balances with purchases, disposals, transfers in/out, realized and unrealized gains/losses. [Table Text Block] Financial Instruments Not Reported at Value [Table Text Block] Financial Instruments Not Reported at Value [Table Text Block] Tabular disclosure of the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined) that are not measured at fair value on a recurring basis. Such disclosures about the financial instruments include the fair value of the required items together with their carrying amounts (as appropriate). The fair value measurements at the reporting date also include the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3). Schedule of Financing Receivable, Allowance for Credit Losses [Table] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Class of Financing Receivable [Axis] Class of Financing Receivable, Type [Axis] Class of Financing Receivable [Domain] Class of Financing Receivable, Type [Domain] Financing Receivable, Allowance for Credit Losses [Line Items] Financing Receivable, Allowance for Credit Losses [Line Items] Balance at beginning of period Charge offs Financing Receivable, Allowance for Credit Losses, Write-downs Balance at end of period Earnings Per Share Earnings Per Share [Text Block]