Entity tax identification number Entity Tax Identification Number Rollovers EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover Maximum Maximum [Member] Forfeited nonvested account, decrease for administrative expense EBP, Forfeited Nonvested Account, Decrease from Administrative Expense Legal Entity [Axis] Legal Entity [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] EBP, Description of Plan [Table] EBP, Description of Plan [Table] Registered Investment Companies Mutual Fund [Member] Subsequent Event Subsequent Event [Member] Self-Directed Brokerage Accounts EBP, Self-Directed Brokerage Account [Member] Total deductions from other activities EBP, Change in Net Asset Available for Benefit, Decrease Note receivable from participant account maximum borrowing amount EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount Fair Value Measurements EBP, Investment, Fair Value and NAV [Text Block] Note receivable from participant account minimum borrowing amount EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount Accrued expenses EBP, Accrued Expense Total investments EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value Subsequent Event Type [Domain] Subsequent Event Type [Domain] Money Market Account Money Market Funds [Member] Level 1 Fair Value, Inputs, Level 1 [Member] Employer contribution maximum vesting percentage EBP, Employer Contribution Maximum Vesting Percentage EBP, Employer Contribution Maximum Vesting Percentage EBP, Investment, Fair Value and NAV [Abstract] Total assets EBP, Asset Assets: EBP, Asset [Abstract] Statistical Measurement [Axis] Statistical Measurement [Axis] EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Trustee EBP, Trustee [Member] Total liabilities EBP, Liability Amendment Flag Amendment Flag Basis of Presentation EBP, Basis of Accounting [Policy Text Block] EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Table] Investment number of shares (in shares) EBP, Investment, Number of Shares Participant loan new interest rate EBP, Participant Loan New Interest Rate EBP, Participant Loan New Interest Rate EBP, Description of Plan and Accounting Change [Abstract] Receivables: EBP, Receivable [Abstract] EBP, Investment, Fair Value and NAV EBP, Investment, Fair Value and NAV [Table Text Block] Change in net asset available for benefit, increase for employer qualified nonelective contribution, cash EBP, Change in Net Asset Available for Benefit, Increase for Employer Qualified Nonelective Contribution, Cash EBP, Change in Net Asset Available for Benefit, Increase for Employer Qualified Nonelective Contribution, Cash Accrued interest on note receivable from participant EBP, Accrued Interest on Note Receivable from Participant EBP, Accrued Interest on Note Receivable from Participant Investments [Domain] Investments [Domain] Use of Estimates EBP, Use of Estimate [Policy Text Block] EBP, Related Party and Party-in-Interest [Domain] EBP, Related Party and Party-in-Interest [Domain] Schedule H, Line 4i – Schedule of Assets (Held At End of Year) EBP, Schedule of Asset Held for Investment [Text Block] Cover [Abstract] Employer, net of forfeitures EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash EBP, Related Party and Party-in-Interest [Axis] EBP, Related Party and Party-in-Interest [Axis] Minimum Minimum [Member] Investment Type [Axis] Investment Type [Axis] Interest income on loans receivable from members EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Maximum employer contribution matching percentage EBP, Maximum Employer Contribution Matching Percentage EBP, Maximum Employer Contribution Matching Percentage Total contributions EBP, Change in Net Asset Available for Benefit, Increase from Contribution Members EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover EBP 001 EBP 001 [Member] EBP 001 Net appreciation in fair value of investments EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment Interest and dividend income EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment EBP, Description of Plan [Line Items] EBP, Description of Plan [Line Items] Plan number EBP, Plan Number EBP, Investment, Fair Value and NAV [Line Items] EBP, Investment, Fair Value and NAV [Line Items] Description of the Plan EBP, Description of Plan [Text Block] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Table] EBP, Statement of Net Asset Available for Benefit [Table] EBP, Schedule of Asset Held for Investment [Line Items] EBP, Schedule of Asset Held for Investment [Line Items] Contributions EBP, Contribution [Policy Text Block] Star Equity Holdings Common Stock EBP, Employer, Common Stock [Member] EBP, Schedule of Asset Held for Investment [Abstract] EBP, Accounting Policy [Table] EBP, Accounting Policy [Table] Total net additions EBP, Change in Net Asset Available for Benefit, Increase Investment, Identifier [Axis] Investment, Identifier [Axis] Administrative expenses EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Self-directed brokerage account, registered investment company, party-in-interest, current value EBP, Self-Directed Brokerage Account, Registered Investment Company, Party-in-Interest, Current Value EBP, Self-Directed Brokerage Account, Registered Investment Company, Party-in-Interest, Current Value Automatic rollover minimum threshold amount EBP, Automatic Rollover Minimum Threshold Amount EBP, Automatic Rollover Minimum Threshold Amount Document Information [Line Items] Document Information [Line Items] Changes in net assets attributed to: EBP, Change in Net Asset Available for Benefit, Increase (Decrease) [Abstract] Employer contribution, participant compensation matched, percentage EBP, Employer Contribution, Participant Compensation Matched, Percentage EBP, Statement of Change in Net Asset Available for Benefit [Abstract] Subsequent Event Type [Axis] Subsequent Event Type [Axis] EBP, Tax Status [Table] EBP, Tax Status [Table] Net increase in net assets available for benefits EBP, Change in Net Asset Available for Benefit, Increase (Decrease) Investment income: EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment [Abstract] EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract] Total receivables EBP, Receivable Employer match receivable EBP, Employer Contribution, Receivable Employer contribution vesting percentage after two years of service EBP, Employer Contribution Vesting Percentage After Two Years Of Service EBP, Employer Contribution Vesting Percentage After Two Years Of Service Benefits paid to members EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Participant loan maximum term EBP, Participant Loan Maximum Term EBP, Participant Loan Maximum Term Current value EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Related Party and Party in Interest Transactions Related Party and Party in Interest Transactions [Policy Text Block] Related Party and Party in Interest Transactions EBP, Statement of Net Asset Available for Benefit [Abstract] EBP, Accounting Policy [Line Items] EBP, Accounting Policy [Line Items] EBP, Tax Status [Abstract] EBP, Employer, Common Stock Fund EBP, Employer, Common Stock Fund [Member] Investments, at fair value EBP, Noninterest-Bearing Cash Investment Options and Restrictions and Investment Valuation and Income Recognition EBP, Investment [Policy Text Block] Fair Value, Inputs, Level 1, Level 2, and Level 3 Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Document Type Document Type Participant contribution vesting percentage EBP, Participant Contribution Vesting Percentage EBP, Participant Contribution Vesting Percentage Entity Central Index Key Entity Central Index Key Automatic rollover maximum threshold amount EBP, Automatic Rollover Maximum Threshold Amount EBP, Automatic Rollover Maximum Threshold Amount Asset held for investment, participant loan, interest rate EBP, Asset Held for Investment, Participant Loan, Interest Rate Common/Collective Trusts Common Collective Trust [Member] EBP, Tax Status [Line Items] EBP, Tax Status [Line Items] Participant loan maximum number outstanding EBP, Participant Loan Maximum Number Outstanding EBP, Participant Loan Maximum Number Outstanding EBP, Subsequent Event [Table] EBP, Subsequent Event [Table] Other Activities: EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] Forfeited nonvested account, decrease for employer contribution EBP, Forfeited Nonvested Account, Decrease from Employer Contribution Members' loans receivable EBP, Note Receivable from Participant Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Summary of Significant Accounting Policies EBP, Summary of Accounting Policy [Text Block] Entity Registrant Name Entity Registrant Name EBP, Subsequent Event [Abstract] Liabilities: EBP, Liability [Abstract] Subsequent Events EBP, Subsequent Event [Text Block] Investment in employer common stock fund to total net assets percentage EBP, Investment In Employer Common Stock Fund To Total Net Assets Percentage EBP, Investment In Employer Common Stock Fund To Total Net Assets Percentage Income Tax Status EBP, Tax Status [Text Block] Note receivable from participant account maximum borrowing to total account percentage EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage EBP, Subsequent Event [Line Items] EBP, Subsequent Event [Line Items] Trustee and Record Keeper Trustee And Record Keeper [Text Block] Trustee And Record Keeper Document Information [Table] Document Information [Table] Member Loans EBP, Note Receivable from Participant [Policy Text Block] Mandatory lump sum distribution threshold amount EBP, Mandatory Lump Sum Distribution Threshold Amount EBP, Mandatory Lump Sum Distribution Threshold Amount Net investment income EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment Contributions: EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution [Abstract] Employer contribution incremental annual vesting percentage EBP, Employer Contribution Incremental Annual Vesting Percentage EBP, Employer Contribution Incremental Annual Vesting Percentage Net assets available for benefits Net assets available for benefits, beginning of year Net assets available for benefits, end of year EBP, Net Asset Available for Benefit Entity [Domain] Entity [Domain] Forfeited nonvested account EBP, Forfeited Nonvested Account Employer contribution, matching percentage EBP, Employer Contribution, Matching Percentage Participant loan maximum term principal residence EBP, Participant Loan Maximum Term Principal Residence EBP, Participant Loan Maximum Term Principal Residence Fair Value Measured at Net Asset Value Per Share Fair Value Measured at Net Asset Value Per Share [Member] EBP, Investment, Fair Value and NAV [Table] EBP, Investment, Fair Value and NAV [Table] EBP, Statement of Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Line Items]