Derivative Instruments and Hedging Activities Disclosure [Abstract] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Level 2 Fair Value, Inputs, Level 2 [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest Rate Swap Interest Rate Swap [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Other Liabilities Other Liabilities [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Notional amount of contract Derivative, Notional Amount Interest Rate Derivative, Fixed Interest Rate Fair Value - asset (liability) Derivative Assets (Liabilities), at Fair Value, Net Notional Amount Statement of Financial Position [Abstract] Statement [Table] Statement [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Centennial Centennial Founders LLC [Member] Centennial Founders LLC Statement [Line Items] Statement [Line Items] Real estate development Inventory, Real Estate, Land and Land Development Costs Common stock, par value per share (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, authorized shares (in shares) Common Stock, Shares Authorized Common stock, issued shares (in shares) Common Stock, Shares, Issued Common stock, outstanding shares (in shares) Common Stock, Shares, Outstanding Stockholders' Equity Note [Abstract] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Restricted Stock Restricted Stock [Member] Class of Stock [Line Items] Class of Stock [Line Items] Weighted average number of shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Common stock (in shares) Weighted Average Number of Shares Outstanding, Basic Common stock equivalents (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Diluted shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Restricted stock excluded from the calculation of dilutive net income per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Share-based Payment Arrangement [Abstract] Number of types of stock grant awards Share Based Compensation Arrangement by Share Based Payment Award, Number of Award Types Share Based Compensation Arrangement by Share Based Payment Award, Number of Award Types Total compensation cost not yet recognized Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Total compensation cost not yet recognized, period for recognition Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Segment Reporting [Abstract] Revenue from External Customers by Products and Services [Table] Revenue from External Customers by Products and Services [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Ranch operations Ranch Operations [Member] Ranch Operations [Member] Revenue from External Customer [Line Items] Revenue from External Customer [Line Items] Total revenues Revenues Total expenses Costs and Expenses Operating results Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Payables and Accruals [Abstract] Accrued Liabilities and Other Accounts Payable and Accrued Liabilities Disclosure [Text Block] Retirement Benefits [Abstract] Retirement Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Mineral resources Mineral Resources [Member] Mineral Resources [Member] Summary of performance share grants with performance conditions Schedule of Share-based Payment Award, Performance Share Awards Granted, by Performance Conditions [Table Text Block] Schedule of Share-based Payment Award, Performance Share Awards Granted, by Performance Conditions [Table Text Block] Summary of stock grant activity Schedule of Nonvested Share Activity [Table Text Block] Summary of stock compensation costs for Employee and NDSI Plans Share-based Payment Arrangement, Cost by Plan [Table Text Block] Farming Farming and Agriculture [Member] Farming and agriculture. Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Long Lived Assets Held-for-sale [Table] Schedule of Long Lived Assets Held-for-sale [Table] Counterparty Name [Axis] Counterparty Name [Axis] Counterparty Name [Domain] Counterparty Name [Domain] AVEK water bank Antelope Valley East Kern Water Agency [Member] Antelope valley east kern water agency. SWP water contracts State Water Project Contracts [Member] State water project contracts. DMB DMB Pacific LLC [Member] DMB Pacific LLC [Member] PEF Pastoria Energy Facility, LLC [Member] Pastoria Energy Facility, LLC [Member] Long Lived Assets Held-for-sale by Asset Type [Axis] Long Lived Assets Held-for-sale by Asset Type [Axis] Long Lived Assets Held-for-sale, Name [Domain] Long Lived Assets Held-for-sale, Name [Domain] Transferable water Transferable Water [Member] Transferable water. Statistical Measurement [Axis] Statistical Measurement [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Maximum Maximum [Member] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Ranchcorp Subsidiaries [Member] Long Lived Assets Held-for-sale [Line Items] Long Lived Assets Held-for-sale [Line Items] AVEK water bank (in acre-feet) Long-term Water Assets, Banked Water Held at Agency Owned Water Bank (Volume) Long-term Water Assets, Banked Water Held at Agency Owned Water Bank (Volume) AVEK water for future delivery (in acre-feet) Long-term Water Assets, Water Contract Rights for Future Delivery (Volume) Long-term Water Assets, Water Contract Rights for Future Delivery (Volume) Long-term water assets (in acre-feet) Long-term Water Assets (Volume) Long-term Water Assets (Volume) Contract renewal optional term Long Term Water Assets, Contract Renewal Optional Term Long Term Water Assets, Contract Renewal Optional Term Cost of purchased water (per acre-foot) Cost of Purchased Water Annual fee increase, percent Long Term Water Assets, Purchased, Annual Fee Increase, Percent Long Term Water Assets, Purchased, Annual Fee Increase, Percent Water assets, volume available for purchase from 2017-2030 (up to) (in acre-feet) Long-term Water Assets (Volume), Amount After Year One Long-term Water Assets (Volume), Amount After Year One Annual option payment, percent Long Term Water Assets, Purchased, Annual Option Payment, Percent Long Term Water Assets, Purchased, Annual Option Payment, Percent Reporting Segments and Related Information Segment Reporting Disclosure [Text Block] Other Liabilities Disclosure [Abstract] Other Liabilities Other Liabilities Disclosure [Text Block] Debt Disclosure [Abstract] Components of long-term debt Schedule of Debt [Table Text Block] Document and Entity Information [Abstract] Document and entity information. Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Document Type Document Type Document Period End Date Document Period End Date Entity Current Reporting Status Entity Current Reporting Status Amendment Flag Amendment Flag Entity Emerging Growth Company Entity Emerging Growth Company Entity Small Business Entity Small Business Entity Shell Company Entity Shell Company Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock Shares Outstanding Entity Common Stock, Shares Outstanding Accounting Policies [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2016-02 Accounting Standards Update 2016-02 [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Number of reportable segments Number of Reportable Segments Lease term Lessee, Operating Lease, Term of Contract Right-of-use asset Operating Lease, Right-of-Use Asset Lease discount rate Lessee, Operating Lease, Discount Rate Operating lease liability Operating Lease, Liability Basis of Presentation Business Description and Basis of Presentation [Text Block] Equity Method Investments and Joint Ventures [Abstract] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Petro Travel Plaza Holdings, LLC Petro Travel Holdings Llc Plaza [Member] Petro travel holdings llc plaza. Five West Parcel, LLC Five West Parcel Llc [Member] Five west parcel llc. 18-19 West, LLC Eighteen Nineteen West Llc [Member] Eighteen nineteen west llc. TRCC/Rock Outlet Center, LLC TRCC/Rock Outlet Center [Member] TRCC/Rock Outlet Center [Member] TRC-MRC 1, LLC TRC-MRC 1 LLC [Member] TRC-MRC 1 LLC [Member] TRC-MRC 2, LLC TRC-MRC 2 LLC [Member] TRC-MRC 2 LLC [Member] TRC-MRC 3, LLC TRC-MRC 3 LLC [Member] TRC-MRC 3 LLC [Member] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Statement of Operations Income Statement [Abstract] Joint Venture Revenues Equity Method Investment, Summarized Financial Information, Revenue Joint Venture Earnings (Loss) Equity Method Investment, Summarized Financial Information, Gross Profit (Loss) TRC Equity in Earnings (Loss) Equity Method Investment Summarized Financial Information, Equity In Earnings (Loss) Equity Method Investment Summarized Financial Information, Equity In Earnings (Loss) Non-cash tenant allowance amortization Equity Method Investment, Summarized Financial Information, Amortization Of Tenant Allowances Equity Method Investment, Summarized Financial Information, Amortization Of Tenant Allowances Balance Sheet Information Joint Venture Assets Equity Method Investment, Summarized Financial Information, Assets Joint Venture Debt Equity Method Investment Summarized Financial Information, Borrowings Equity Method Investment Summarized Financial Information, Borrowings Joint Venture Equity Equity Method Investment Summarized Financial Information, Equity TRC Equity Equity Method Investment Summarized Financial Information, Investment Equity Method Investment Summarized Financial Information, Investment Statement of Stockholders' Equity [Abstract] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Total Stockholders' Equity Parent [Member] Common Stock Common Stock [Member] Additional Paid-In Capital Additional Paid-in Capital [Member] Accumulated Other Comprehensive (Loss) Income AOCI Attributable to Parent [Member] Retained Earnings Retained Earnings [Member] Noncontrolling Interest Noncontrolling Interest [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning Balance, value Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Beginning Balance (in shares) Shares, Outstanding Net income (loss) Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Rights offering costs Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs Restricted stock issuance Stock Issued During Period, Value, Restricted Stock Award, Gross Restricted stock issuance (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Gross Stock compensation APIC, Share-based Payment Arrangement, Increase for Cost Recognition Shares withheld for taxes and tax benefit of vested shares Share-based Payment Arrangement, Decrease for Tax Withholding Obligation Shares withheld for taxes and tax benefit of vested shares (in shares) Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation Ending Balance, value Ending Balance (in shares) WRMWSD - Contracts with Company Wheeler Ridge Maricopa Water Storage District [Member] Wheeler Ridge Maricopa Water Storage District [Member] Tejon-Castac Water District Tejon-Castac Water District [Member] Tejon-Castac Water District [Member] Long-term Water Assets [Line Items] Long-term Water Assets [Line Items] Long-term Water Assets [Line Items] Banked water and water for future delivery Long-term Water Assets, Banked Water and Water Contract Rights [Abstract] Long-term Water Assets, Banked Water and Water Contract Rights [Abstract] AVEK water bank Company water bank Long-term Water Assets, Banked Water Held at Company Owned Water Bank (Volume) Long-term Water Assets, Banked Water Held at Company Owned Water Bank (Volume) Transferable water Long-term Water Assets, Transferrable Water (Volume) Long-term Water Assets, Transferrable Water (Volume) Banked water and water for future delivery Long-term Water Assets, Banked Water and Water Contract Rights (Volume) Long-term Water Assets, Banked Water and Water Contract Rights (Volume) Water contracts and purchased water Long-term Water Assets, Water Contracts (Volume) Long-term Water Assets, Water Contracts (Volume) Total purchased water contracts Long-term Water Assets, Intangible Water Contracts (Volume) Long-term Water Assets, Intangible Water Contracts (Volume) Total purchased and contracted water sources in acre feet Long Term Water Assets, Contracts with Company Long Term Water Assets, Contracts with Company Investments, Debt and Equity Securities [Abstract] Summary of available-for-sale securities Debt Securities, Available-for-sale [Table Text Block] Summary of maturities, at par, of marketable securities by year Investments Classified by Contractual Maturity Date [Table Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Notes payable Secured Debt [Member] Other borrowings Notes Payable to Banks [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Long-term debt consists of: Long-term Debt, by Current and Noncurrent [Abstract] Total short-term and long-term debt Long-term Debt, Gross Less: line-of-credit and current maturities of long-term debt Long-term Debt, Current Maturities Less: deferred loan costs Debt Issuance Costs, Net Long-term debt, less current portion Long-term Debt, Excluding Current Maturities Components of segment revenues Revenue from External Customers by Products and Services [Table Text Block] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments Operating Segments [Member] Corporate expenses Corporate, Non-Segment [Member] Real estate - commercial/industrial Commercial and Industrial [Member] Commercial and industrial. Real estate - resort/residential Resort and Residential Real Estate [Member] Resort and Residential Real Estate [Member] Revenues: Revenues [Abstract] Total revenues Revenue from Contract with Customer, Excluding Assessed Tax Costs and Expenses: Costs and Expenses [Abstract] Operating loss Operating Income (Loss) Other Income: Nonoperating Income (Expense) [Abstract] Investment income Investment Income, Net Other income (loss), net Other Nonoperating Income (Expense) Total other income Nonoperating Income (Expense) Loss from operations before equity in earnings of unconsolidated joint ventures Equity in earnings of unconsolidated joint ventures, net Income (Loss) from Equity Method Investments Income (loss) before income tax expense Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income tax expense (benefit) Income Tax Expense (Benefit) Net income (loss) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income (loss) attributable to non-controlling interest Net Income (Loss) Attributable to Noncontrolling Interest Net income (loss) attributable to common stockholders Net Income (Loss) Attributable to Parent Net income (loss) per share attributable to common stockholders, basic (in dollars per share) Earnings Per Share, Basic Net income (loss) per share attributable to common stockholders, diluted (in dollars per share) Earnings Per Share, Diluted Interest Rate Swap Derivative Instruments and Hedging Activities Disclosure [Text Block] 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 Pension Plan [Member] SERP Supplemental Employee Retirement Plan [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Earnings (cost) components: Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Interest cost Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Net amortization and deferral Defined Benefit Plan, Amortization of Gain (Loss) Total net periodic pension earnings Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Real Estate [Abstract] Schedule of Real Estate Schedule of Real Estate Properties [Table Text Block] Income Tax Disclosure [Abstract] Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Income taxes receivable Income Taxes Receivable Income tax payments Income Taxes Paid, Net Schedule of Interest Rate Derivatives Schedule of Interest Rate Derivatives [Table Text Block] Schedule of water revenues and cost of sales Schedule of Water Revenues and Cost of Sales [Table Text Block] Schedule of Water Revenues and Cost of Sales [Table Text Block] Tangible water assets Tangible Water Assets [Table Text Block] Tangible Water Assets [Table Text Block] Schedule of finite-lived intangible assets Schedule of Finite-Lived Intangible Assets [Table Text Block] Components of water assets Disclosure of Long Lived Assets Held-for-sale [Table Text Block] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-sale [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Cost Reported Value Measurement [Member] Fair Value Estimate of Fair Value Measurement [Member] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Certificates of deposit Certificates of Deposit [Member] U.S. Treasury and agency notes US Treasury and Government Short-term Debt Securities [Member] Corporate notes Corporate Note Securities [Member] Municipal notes Municipal Bonds [Member] Level 1 Fair Value, Inputs, Level 1 [Member] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] Marketable Securities with unrecognized losses for less than 12 months Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Marketable Securities with unrecognized losses for more than 12 months Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Marketable Securities with unrecognized gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Total Available-for-sale Securities Debt Securities, Available-for-sale Line of Credit Facility [Table] Line of Credit Facility [Table] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Term Notes Medium-term Notes [Member] Revolving line of credit Revolving Credit Facility [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] Selected LIBOR rate Selected LIBOR Rate [Member] Selected LIBOR Rate [Member] LIBOR for a fixed rate term Fixed Term LIBOR [Member] Fixed Term LIBOR [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Promissory note agreement Notes Payable, Other Payables [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Line of credit amount Line of Credit Facility, Current Borrowing Capacity Interest rate on line of credit, variable rate Debt Instrument, Basis Spread on Variable Rate Interest pay rate Commitment fee percentage Line of Credit Facility, Commitment Fee Percentage RLC outstanding balance Number of debt covenants Debt Instrument, Covenant Compliance, Number of Covenants Debt Instrument, Covenant Compliance, Number of Covenants Debt equity ratio Debt Covenant Compliance, Debt Equity Ratio Debt Covenant Compliance, Debt Equity Ratio Debt service coverage ratio Debt Covenant Compliance, Debt Service Coverage Ratio Debt Covenant Compliance, Debt Service Coverage Ratio Minimum liquid assets Debt Covenant Compliance, Liquid Assets, Minimum Debt Covenant Compliance, Liquid Assets, Minimum Debt instrument face amount Debt Instrument, Face Amount Stated interest rate Debt Instrument, Interest Rate, Stated Percentage Periodic principal and interest payments Debt Instrument, Periodic Payment Long-term debt Long-term Debt Schedule of Accrued Liabilities and Other Schedule of Accrued Liabilities [Table Text Block] Equity Stockholders' Equity Note Disclosure [Text Block] Schedule of weighted average number of shares outstanding Schedule of Weighted Average Number of Shares [Table Text Block] Other Liabilities Other Liabilities [Abstract] Pension and supplemental executive retirement plan liability Liability, Pension and Other Postretirement and Postemployment Benefits, Noncurrent Interest rate swap liability Derivative Liability, Noncurrent Excess joint venture distributions and other Other Sundry Liabilities, Noncurrent Total Other Liabilities, Noncurrent Derivative asset, noncurrent Derivative Asset, Noncurrent Stock Compensation - Restricted Stock and Performance Share Grants Stock Compensation Restricted Stock and Performance Share Grants [Text Block] Stock compensation restricted stock and performance share grants. Fair market value of investment securities exceeds cost basis Debt Securities, Available for Sale Securities, Fair Market Value Exceeds Cost Basis, by Amount Debt Securities, Available for sale securities, fair market value exceeds cost basis, by amount. Gross unrealized holding gains Gross unrealized holding losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Unrealized gain (loss) on available-for-sale securities Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax Estimated tax expense (benefit) of change in value of available-for-sale securities Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax Marketable Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Components of net periodic pension cost Schedule of Net Benefit Costs [Table Text Block] Statement of Cash Flows [Abstract] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Land Land [Member] Value of land contributed Contribution of Property Number of acres for development Development of Building Development of building. Transaction costs Contribution of Property, Transaction Costs Contribution of Property, Transaction Costs Profit margin Gross Profit Deferred profit margin Equity Method Investment, Deferred Gain on Sale Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Performance share grants Performance Shares [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Summary of stock grant activity: Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Stock grants outstanding beginning of the year at target achievement (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number New stock grants/additional shares due to maximum achievement (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Vested grants (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Expired/forfeited grants (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Stock grants outstanding end of the year at target achievement (in shares) Segment losses Banked water and water for future delivery Banked Water and Water for Future Delivery [Member] Banked water and water for future delivery. Total water held for future use at cost Tangible Water Assets, Banked Water and Water Contract Rights Tangible Water Assets, Banked Water and Water Contract Rights Real Estate Real Estate Disclosure [Text Block] Certificates of deposit U.S. Treasury and agency notes Corporate notes Municipal notes Summary of maturities, at par, of marketable securities Available For Sale Debt Securities, Fiscal Year Maturity [Abstract] Available for sale debt securities, fiscal year maturity. 2019 Debt Securities, Available for Sale Securities Maturities Year One at Par Debt Securities, Available for sale securities maturities, year one, at par. 2020 Debt Securities, Available for Sale Securities Maturities, Year Two, at Par Debt Securities, Available for sale securities maturities, year two, at par. 2021 Debt Securities, Available for Sale Securities Maturities, Year Three, at Par Debt Securities, Available for sale securities maturities, year three, at par. Total Debt Securities, Available for Sale Securities Maturities at Par Debt Securities, Available for sale securities maturities, at par. Other Liabilities Other Liabilities [Table Text Block] Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Domain] Defined Benefit Plan, Plan Assets, Category [Domain] Equities Defined Benefit Plan, Equity Securities [Member] Treasury/Corporate Notes Defined Benefit Plan, Debt Security [Member] Money market funds Money Market Funds [Member] Service period Defined Benefit Plan, Average Service Period Defined Benefit Plan, Average Service Period Contributions to defined benefit plan Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year Current investment policy targets: Defined Benefit Plan, Plan Assets, Allocations [Abstract] Current investment mix Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage Assumptions used in determining periodic pension cost: Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] Discount rate Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Expected long-term rate of return on plan assets Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets Recent and Newly Adopted Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] 1998 Plan Stock Incentive Plan 1998 [Member] Stock incentive plan. NDSI Plan Non-Employee Director Stock Incentive Plan [Member] Non-employee director stock incentive plan. Stock compensation costs, expensed Share-based Payment Arrangement, Expense Stock compensation costs, capitalized Share-based Payment Arrangement, Amount Capitalized Total Stock Compensation Costs Share-based Payment Arrangement, Accelerated Cost Commitments and Contingencies Disclosure [Abstract] Loss Contingencies [Table] Loss Contingencies [Table] Scenario [Axis] Scenario [Axis] Scenario [Domain] Scenario [Domain] Scenario, Forecast Forecast [Member] KCWA Kern County Water Agency [Member] Kern County Water Agency [Member] West CFD West Community Facilities Districts [Member] West community facilities districts. East CFD East Community Facilities Districts [Member] -- None. No documentation exists for this element. -- Standby letter of credit Standby Letters of Credit [Member] Litigation Case [Axis] Litigation Case [Axis] Litigation Case [Domain] Litigation Case [Domain] Antelope Valley Groundwater Cases Antelope Valley Groundwater Cases [Member] Antelope Valley Groundwater Cases [Member] Litigation Status [Axis] Litigation Status [Axis] Litigation Status [Domain] Litigation Status [Domain] Settled Litigation Settled Litigation [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Amount paid for water contracts Repayments of Long-term Capital Lease Obligations Long-term water assets (volume) Contractual obligation for future water payments Contractual Obligation Estimated future payments Capital Leases, Future Minimum Payments, Net Minimum Payments Incentive fee on contract termination, measurement period from entitlement achievement date Contract Termination, Incentive Fee Calculation, Measurement Period From Entitlement Achievement Date Contract Termination, Incentive Fee Calculation, Measurement Period From Entitlement Achievement Date Number of community facility districts Number of Community Facility Districts Number of Community Facility Districts Acres of land related to land liens Acres of Land Related to Land Liens Acres of land related to land liens. Bond debt sold by TRPFFA Long-term Line of Credit Additional bond debt authorized to be sold in future Letters of credit outstanding amount Letters of Credit Outstanding, Amount Letter of credit period Letter of credit period Letter of credit period. Letter of credit renewal period Letter of Credit Renewal Period Letter of credit renewal period. Annual cost related to the letter of credit Additional reimbursement funds Additional Reimbursement Funds Additional reimbursement funds. Special taxes paid Taxes, Other Number of parties in agreement for settlement Loss Contingency, Number of Plaintiffs Percentage of current water usage with the adjudication boundary (more than) Loss Contingency, Settlement, Percent of Water Use Within the Adjudication Boundary Loss Contingency, Settlement, Percent of Water Use Within the Adjudication Boundary Acres of land transferred Acres of Land Transferred Acres of Land Transferred Investment in Unconsolidated and Consolidated Joint Ventures Equity Method Investments and Joint Ventures Disclosure [Text Block] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Contract-based intangible assets Contract-Based Intangible Assets [Member] Dudley-Ridge water rights Dudley Ridge Water Rights [Member] Dudley Ridge Water Rights [Member] Nickel water rights Nickel Water Rights [Member] Nickel Water Rights [Member] Tulare Lake Basin water rights Tulare Lake Basin Water Rights [Member] Tulare Lake Basin Water Rights [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Costs Finite-Lived Intangible Assets, Gross Accumulated Depreciation Finite-Lived Intangible Assets, Accumulated Amortization Net cost of purchased water contracts Finite-Lived Intangible Assets, Net Total tangible water assets Net investment in water assets Long Term Assets Held for Future Use or Sale Long term assets held for future use or sale. Condensed statements of operations and balance sheet information of consolidated and unconsolidated joint ventures Schedule of Condensed Income Statement and Balance Sheet Related to Joint Ventures [Table Text Block] Schedule of condensed income statement and balance sheet related to joint ventures. Below threshold performance (in shares) Performance Awards Granted with Performance Conditions, Number of Shares to be Issued, Below Threshold Performance Performance Awards Granted with Performance Conditions, Number of Shares to be Issued, Below Threshold Performance Threshold performance (in shares) Performance Awards Granted with Performance Conditions, Minimum Number of Shares to be Issued, at Threshold Performance Performance Awards Granted with Performance Conditions, Minimum Number of Shares to be Issued, at Threshold Performance Target performance (in shares) Performance Awards Granted with Performance Conditions, Number of Shares to be Issued, at Target Performance Performance Awards Granted with Performance Conditions, Number of Shares to be Issued, at Target Performance Maximum performance (in shares) Performance Awards Granted with Performance Conditions, Maximum Number of Shares to be Issued, at Maximum Performance Performance Awards Granted with Performance Conditions, Maximum Number of Shares to be Issued, at Maximum Performance Accrued vacation Accrued Vacation, Current Accrued paid personal leave Accrued Paid Personal Leave, Current Accrued Paid Personal Leave, Current Accrued bonus Accrued Bonuses, Current Other Other Employee-related Liabilities, Current Total Other Accrued Liabilities, Current Line of Credit and Long-Term Debt Debt Disclosure [Text Block] Acre-Feet Sold (in acre-feet) Long Term Water Assets, Water Sold (Volume) Long Term Water Assets, Water Sold (Volume) Revenues Revenue from Purchased Water Revenue from Purchased Water Cost of sales Profit Gross Profit from Purchased Water Gross Profit from Purchased Water Statement of Comprehensive Income [Abstract] Net income (loss) Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax [Abstract] Unrealized gain (loss) on available-for-sale securities Unrealized (loss) gain on interest rate swap Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax Other comprehensive (loss) income before taxes Other Comprehensive Income (Loss), before Tax Benefit (provision) for income taxes related to other comprehensive income items Other Comprehensive Income (Loss), Tax Other comprehensive (loss) income Comprehensive (loss) income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive income (loss) attributable to non-controlling interests Comprehensive (loss) income attributable to common stockholders Comprehensive Income (Loss), Net of Tax, Attributable to Parent Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Name of Property [Axis] Name of Property [Axis] Name of Property [Domain] Name of Property [Domain] Mountain Village Tejon Mountain Village Llc [Member] Tejon mountain village llc. Grapevine Grapevine [Member] Grapevine [Member] Tejon Ranch Commerce Center Tejon Ranch Commerce Center [Member] Tejon Ranch Commerce Center [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Tejon Ranch Commerce Center Inventory, Real Estate, Improvements, Gross Inventory, Real Estate, Improvements, Gross Less accumulated depreciation Inventory, Real Estate, Improvements, Accumulated Depreciation Inventory, Real Estate, Improvements, Accumulated Depreciation Real estate and improvements - held for lease, net Inventory, Real Estate, Improvements Cash and Cash Equivalents, Period Increase (Decrease) [Abstract] Cash and Cash Equivalents, Period Increase (Decrease) [Abstract] Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Adjustments to reconcile net income to net cash (used in) provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization Amortization of premium/discount of marketable securities Accretion (Amortization) of Discounts and Premiums, Investments Equity in earnings of unconsolidated joint ventures, net Non-cash retirement plan expense Pension and Other Postretirement Benefits Cost (Reversal of Cost) Non-cash profits recognized from land contribution Gain (Loss) on Disposition of Other Assets Loss on sale of property plant and equipment Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Stock compensation expense Share-based Payment Arrangement, Noncash Expense Excess tax benefit from stock-based compensation Excess Tax Benefit from Share-based Compensation, Operating Activities Changes in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Receivables, inventories, prepaids and other assets, net Increase (Decrease) in Operating Assets Current liabilities, net Increase (Decrease) in Operating Liabilities Net cash (used in) provided by operating activities Net Cash Provided by (Used in) Operating Activities Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Maturities and sales of marketable securities Proceeds from Sale and Maturity of Marketable Securities Funds invested in marketable securities Payments to Acquire Marketable Securities Real estate and equipment expenditures Payments to Acquire Property, Plant, and Equipment Reimbursement proceeds from Community Facilities District Payments for (Proceeds from) Other Investing Activities, Business Three Payments for (Proceeds from) Other Investing Activities, Business Three Investment in unconsolidated joint ventures Payments to Acquire Interest in Joint Venture Distribution of equity from unconsolidated joint ventures Proceeds from Equity Method Investment, Distribution, Return of Capital Investments in long-term water assets Payments to Acquire Other Investments Other Payments for (Proceeds from) Other Investing Activities 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] Repayments of long-term debt Repayments of Long-term Debt Rights offering costs Payments of Stock Issuance Costs Taxes on vested stock grants Proceeds from (Payments for) Other Financing Activities Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities 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, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash and cash equivalents at end of period Supplemental cash flow information Supplemental Cash Flow Information [Abstract] Accrued capital expenditures included in current liabilities Change In Capital Expenditures Incurred But Not Yet Paid Change In Capital Expenditures Incurred But Not Yet Paid Contribution to unconsolidated joint venture Long term deferred profit on land contribution Deferred Gain On Contribution Of Land Deferred Gain On Contribution Of Land ASSETS Assets [Abstract] Current Assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Marketable securities - available-for-sale Debt Securities, Available-for-sale, Current Accounts receivable Accounts Receivable, after Allowance for Credit Loss, Current Inventories Inventory, Net Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Real estate and improvements - held for lease, net Real estate development (includes $102,415 at June 30, 2019 and $100,311 at December 31, 2018, attributable to Centennial Founders, LLC, Note 15) Property and equipment, net Property, Plant and Equipment, Net Investments in unconsolidated joint ventures Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Net investment in water assets Deferred tax assets Deferred Income Tax Assets, Net Other assets Other Assets, Noncurrent TOTAL ASSETS Assets LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Current Liabilities: Liabilities, Current [Abstract] Trade accounts payable Accounts Payable, Current Accrued liabilities and other Deferred income Contract with Customer, Liability, Current Current maturities of long-term debt Debt, Current Total current liabilities Liabilities, Current Long-term deferred gains Contract with Customer, Liability, Noncurrent Other liabilities Total liabilities Liabilities Commitments and contingencies Commitments and Contingencies Equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Tejon Ranch Co. Stockholders’ Equity Stockholders' Equity Attributable to Parent [Abstract] Issued and outstanding shares - 26,033,402 at June 30, 2019 and 25,972,080 at December 31, 2018 Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Retained earnings Retained Earnings (Accumulated Deficit) Total Tejon Ranch Co. Stockholders’ Equity Stockholders' Equity Attributable to Parent Non-controlling interest Stockholders' Equity Attributable to Noncontrolling Interest Total equity TOTAL LIABILITIES AND EQUITY Liabilities and Equity Majestic Realty Co. Majestic Realty Co. [Member] Majestic Realty Co. [Member] TRCC-East TRCC-East [Member] TRCC-East [Member] Rockefeller Joint Ventures Rockefeller Joint Ventures [Member] Rockefeller joint ventures. Building Development Building Improvements [Member] Line of Credit Line of Credit [Member] Ownership [Axis] Ownership [Axis] Ownership [Domain] Ownership [Domain] Equity in earnings (loss) Unconsolidated joint ventures, ownership interest Equity Method Investment, Ownership Percentage Right and share of profit and loss Equity Method Investment, Right and Share of Income and (Loss) Equity Method Investment, Right and Share of Income and (Loss) Equity Number of joint venture contracts Number of Joint Venture Contracts Number of joint venture contracts. Lease agreement, rentable space Joint Venture, Percentage of Rentable Space Occupied Joint Venture, Percentage of Rentable Space Occupied Debt Area of building owned and leased Lease of Building Lease of building. Deficit balance Distributions in Excess of Investment in Unconsolidated Joint Venture Distributions in Excess of Investment in Unconsolidated Joint Venture Construction Loan Equity Method Investment Summarized Financial Information, Line of Credit Facility, Maximum Borrowing Capacity Equity Method Investment Summarized Financial Information, Line of Credit Facility, Maximum Borrowing Capacity Investment in unconsolidated joint ventures Equity Method Investments Development of land in TRCC including pursuing foreign trade zone (up to) Area of Land Option to extend, joint venture Joint Venture, Additional Option to Extend Joint Venture, Additional Option to Extend Number of acres for development Contribution for Joint Venture for Future Development Contribution for joint venture for future development. Summarized financial information, maximum borrowing capacity Equity Method Investment, Summarized Financial Information, Maximum Borrowing Capacity Equity Method Investment, Summarized Financial Information, Maximum Borrowing Capacity Noncontrolling interest balance Noncontrolling Interest in Joint Ventures Consolidated joint venture, ownership interest Noncontrolling Interest, Ownership Percentage by Parent Related Party Transactions [Abstract] Related Party Transactions Related Party Transactions Disclosure [Text Block] Long-Term Water Assets Property, Plant and Equipment Disclosure [Text Block] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Income Taxes Income Tax Disclosure [Text Block] Commercial revenues Commercial revenues and equity in earnings of unconsolidated joint ventures Revenues and Income (Loss) from Equity Method Investments Revenues and Income (Loss) from Equity Method Investments Operating results from commercial and unconsolidated joint ventures