Revenue Recognition and Deferred Revenue [Abstract] Disaggregation of Revenue [Table Text Block] Disaggregation of Revenue [Table Text Block] Contract with Customer, Asset and Liability [Table Text Block] Contract with Customer, Asset and Liability [Table Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Text Block] Goodwill and Intangible Assets Disclosure [Text Block] Schedule of Goodwill [Table Text Block] Schedule of Goodwill [Table Text Block] Schedule of Finite-Lived Intangible Assets [Table Text Block] Schedule of Finite-Lived Intangible Assets [Table Text Block] Capitalized Contract Cost, Net Capitalized Contract Cost, Net Unbilled Receivables, Current Unbilled Receivables, Current Estimated profits on contracts in process Estimated profits on contracts in process Estimated profits on contracts in process Billings to Date Billings to Date Billings to Date on jobs in process Contract with Customer, Asset, Net, Current Contract Asset (Liability), Net Contract Asset (Liability), Net Costs in Excess of Billings, Current Costs in Excess of Billings, Current Billings in Excess of Cost, Current Billings in Excess of Cost, Current Contract with Customer, Liability, Revenue Recognized Contract with Customer, Liability, Revenue Recognized Performance Obligation Next 12 Months Performance Obligation Next 12 Months Performance Obligation Next 12 Months Revenue, Remaining Performance Obligation, Amount Revenue, Remaining Performance Obligation, Amount Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] industrial Services [Member] industrial Services [Member] industrial Services [Member] Custom Power Solutions [Member] Custom Power Solutions [Member] Custom Power Solutions [Member] Single Family Contracts [Member] Single Family Contracts [Member] Single Family Type Customer Contracts Multi Family and Other [Member] Multi Family and Other [Member] Multi Family and Other Customer Contract Type Contract with Customer, Basis of Pricing [Axis] Contract with Customer, Basis of Pricing [Axis] Contract with Customer, Basis of Pricing [Domain] Contract with Customer, Basis of Pricing [Domain] Fixed-price Contract [Member] Fixed-price Contract [Member] Time-and-materials Contract [Member] Time-and-materials Contract [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Commercial and Industrial [Member] Commercial and Industrial [Member] Commercial and Industrial [Member] Communications [Member] Communications [Member] Communications [Member] Infrastructure Solutions [Member] Infrastructure Solutions [Member] Infrastructure Solutions [Member] Residential [Member] Residential [Member] Residential [Member] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Revenues Revenues DEI [Abstract] DEI [Abstract] 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 Amendment Flag Amendment Flag 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 Entity Current Reporting Status Entity Current Reporting Status Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Shell Company Entity Shell Company Inventory Disclosure [Abstract] Inventory, Raw Materials, Gross Inventory, Raw Materials, Gross Inventory, Work in Process, Gross Inventory, Work in Process, Gross Inventory, Finished Goods, Gross Inventory, Finished Goods, Gross Other Inventory, Gross Other Inventory, Gross Inventory, Net Inventory, Net Retirement Benefits [Abstract] Defined Contribution Plan, Cost Defined Contribution Plan, Cost Liability, Defined Benefit Plan Liability, Defined Benefit Plan Earnings Per Share [Abstract] Undistributed Earnings (Loss) Available to Common Shareholders, Basic Undistributed Earnings (Loss) Available to Common Shareholders, Basic Noncontrolling Interest, Period Increase (Decrease) Noncontrolling Interest, Period Increase (Decrease) Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Comprehensive income attributable to IES Holdings, Inc. Net Income (Loss) Attributable to Parent Weighted Average Number of Shares Outstanding, Basic Weighted Average Number of Shares Outstanding, Basic Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Weighted Average Number of Shares Outstanding, Diluted Weighted Average Number of Shares Outstanding, Diluted Earnings Per Share, Basic Earnings Per Share, Basic Earnings Per Share, Diluted Earnings Per Share, Diluted Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Investments, Debt and Equity Securities [Abstract] Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule of Segment Reporting Information, by Segment [Table Text Block] Income Statement [Abstract] Cost of services Cost of Goods and Services Sold Gross profit Gross Profit Selling, general and administrative expenses Selling, General and Administrative Expense Contingent consideration Business Combination, Integration Related Costs Loss (gain) on sale of assets Gain (Loss) on Disposition of Assets Operating income (loss) Operating Income (Loss) Interest expense Interest Expense Other (income) expense, net Other Nonoperating Income (Expense) Income (loss) from operations before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Provision for (benefit from) income taxes Income Tax Expense (Benefit) Net income (loss) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income attributable to noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest Weighted Average Number of Shares Outstanding, Diluted Statement of Cash Flows [Abstract] Net income (loss) Bad debt expense Accounts Receivable, Credit Loss Expense (Reversal) Deferred financing cost amortization Amortization of Debt Issuance Costs Depreciation and amortization Depreciation, Depletion and Amortization Non-cash compensation expense Share-based Payment Arrangement, Noncash Expense Deferred income taxes Deferred Income Tax Expense (Benefit) Accounts receivable Increase (Decrease) in Accounts Receivable Inventories Increase (Decrease) in Inventories Costs and estimated earnings in excess of billings Increase (Decrease) in Contract with Customer, Asset Prepaid expenses and other current assets Increase (Decrease) in Other Current Assets Other non-current assets Increase (Decrease) in Other Noncurrent Assets Accounts payable and accrued expenses Increase (Decrease) in Other Accounts Payable and Accrued Liabilities Billings in excess of costs and estimated earnings Increase (Decrease) in Contract with Customer, Liability Other non-current liabilities Increase (Decrease) in Other Noncurrent Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Purchases of property and equipment Payments to Acquire Productive Assets Proceeds from sale of assets Proceeds from Sale of Productive Assets Cash paid in conjunction with business combinations Payments to Acquire Businesses, Net of Cash Acquired Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Borrowings of debt Proceeds from Issuance of Long-term Debt and Capital Securities, Net Repayments of debt Repayment of Long-term Debt, Long-term Lease Obligation, and Capital Security Distribution to noncontrolling interests Proceeds from (Payments to) Noncontrolling Interests Purchase of treasury stock Payments for Repurchase of Common Stock Options exercised Proceeds from Stock Options Exercised Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS Cash and Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect CASH, CASH EQUIVALENTS and RESTRiCTED CASH, beginning of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents CASH, CASH EQUIVALENTS and RESTRICTED CASH, end of period Cash paid for interest Interest Paid, Including Capitalized Interest, Operating and Investing Activities Cash paid for income taxes (net) Income Taxes Paid, Net Business Combinations [Abstract] Business Combination Disclosure [Text Block] Business Combination Disclosure [Text Block] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Corporate Segment [Member] Corporate Segment [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Operating income (loss) Depreciation and amortization expense Depreciation Capital expenditures Total assets Assets Fair Value Disclosures [Abstract] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [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] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Fair Value, Inputs, Level 3 [Member] Fair Value, Inputs, Level 3 [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] Assets, Fair Value Disclosure Assets, Fair Value Disclosure Financial and Nonfinancial Liabilities, Fair Value Disclosure Financial and Nonfinancial Liabilities, Fair Value Disclosure Business Combination, Contingent Consideration, Liability, Noncurrent Business Combination, Contingent Consideration, Liability, Noncurrent Fair Value, Net Asset (Liability) Fair Value, Net Asset (Liability) Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings Revenue from External Customers by Products and Services [Table Text Block] Revenue from Contract with Customer [Text Block] Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock [Member] Common Stock [Member] Treasury Stock [Member] Treasury Stock [Member] Additional Paid-in Capital [Member] Additional Paid-in Capital [Member] Retained Earnings [Member] Retained Earnings [Member] Statement [Line Items] Statement [Line Items] Stockholders' Equity Attributable to Parent Stockholders' Equity Attributable to Parent Shares, Issued Shares, Issued Issuances under compensation plans Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture Issuances under compensation plans, shares Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture Restricted stock grant Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Restricted stock grant, shares Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Cumulative effect adjustment from adoption of new accounting standard Cumulative Effect on Retained Earnings, Net of Tax Acquisition of treasury stock Treasury Stock, Value, Acquired, Cost Method Acquisition of treasury stock, shares Treasury Stock, Shares, Acquired Options exercised Stock Issued During Period, Value, Stock Options Exercised Options exercised, shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Non-cash compensation APIC, Share-based Payment Arrangement, Increase for Cost Recognition Decrease in noncontrolling interest Noncontrolling Interest, Change in Redemption Value Net income (loss) attributable to IES Holdings, Inc. Stockholders' Equity Attributable to Parent Shares, Issued Accounting Policies [Abstract] Noncontrolling Interest, Ownership Percentage by Parent Noncontrolling Interest, Ownership Percentage by Parent Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners Redeemable Noncontrolling Interest, Equity, Redemption Value Redeemable Noncontrolling Interest, Equity, Redemption Value Noncontrolling Interest, Change in Redemption Value Unrecognized Tax Benefits, Period Increase (Decrease) Unrecognized Tax Benefits, Period Increase (Decrease) Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Statement of Financial Position [Abstract] Cash and cash equivalents Accounts receivable Accounts Receivable, after Allowance for Credit Loss, Current Retainage Contract Receivable Retainage Inventories Costs and estimated earnings in excess of billings Costs in Excess of Billings Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Total current assets Assets, Current Property and equipment, net Property, Plant and Equipment, Net Goodwill Goodwill Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Deferred tax assets Deferred Tax Assets, Net Other non-current assets Other Assets, Noncurrent Total assets Accounts payable and accrued expenses Accounts Payable and Accrued Liabilities, Current Billings in excess of costs and estimated earnings Total current liabilities Liabilities, Current Long-term debt Long-term Debt, Excluding Current Maturities Other non-current liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Noncontrolling interest Stockholders' Equity Attributable to Noncontrolling Interest Preferred stock, value Preferred Stock, Value, Issued Common stock, value Common Stock, Value, Issued Treasury stock, value Treasury Stock, Value Additional paid-in capital Additional Paid in Capital Retained earnings Retained Earnings (Accumulated Deficit) Total stockholders' equity Total liabilities and stockholders' equity Liabilities and Equity Segment Reporting Disclosure [Text Block] Segment Reporting Disclosure [Text Block] Inventory Disclosure [Text Block] Inventory Disclosure [Text Block] Business Description and Basis of Presentation [Text Block] Business Description and Basis of Presentation [Text Block] Accounts Receivable, Allowance for Credit Loss, Current Accounts Receivable, Allowance for Credit Loss, Current Preferred Stock, Par or Stated Value Per Share Preferred Stock, Par or Stated Value Per Share 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, Par or Stated Value Per Share Common Stock, Par or Stated Value Per Share Common Stock, Shares Authorized Common Stock, Shares Authorized Common Stock, Shares, Issued Common Stock, Shares, Issued Common Stock, Shares, Outstanding Common Stock, Shares, Outstanding Treasury Stock, Shares Treasury Stock, Shares Debt Disclosure [Abstract] Equity [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Title of Individual [Axis] Title of Individual [Axis] Title of Individual [Domain] Title of Individual [Domain] Chief Executive Officer [Member] Chief Executive Officer [Member] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] Share Repurchase Program [Domain] Stock Repurchase Plan [Member] Stock Repurchase Plan Equity Incentive Plan [Member] Equity Incentive Plan [Member] Equity Incentive Plan [Member] Grantee Status [Axis] Grantee Status [Axis] Grantee Status [Domain] Grantee Status [Domain] Share-based Payment Arrangement, Employee [Member] Share-based Payment Arrangement, Employee [Member] Share-based Payment Arrangement, Nonemployee [Member] Share-based Payment Arrangement, Nonemployee [Member] Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Restricted Stock [Member] Restricted Stock [Member] Phantom Share Units (PSUs) [Member] Phantom Share Units (PSUs) [Member] Performance Based Phantom Shares [Member] 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] Treasury Stock, Shares, Acquired Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period Share-based Payment Arrangement, Expense Share-based Payment Arrangement, Expense Shares, Outstanding Shares, Outstanding Common Stock, Capital Shares Reserved for Future Issuance Common Stock, Capital Shares Reserved for Future Issuance Stock Repurchase Program, Number of Shares Authorized to be Repurchased Stock Repurchase Program, Number of Shares Authorized to be Repurchased Treasury Stock Acquired, Average Cost Per Share Treasury Stock Acquired, Average Cost Per Share Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Cost Method Investments Cost Method Investments Fair Value Disclosures [Text Block] Fair Value Disclosures [Text Block] Debt Disclosure [Text Block] Debt Disclosure [Text Block] Earnings Per Share [Text Block] Earnings Per Share [Text Block] Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] Visalia [Member] Visalia [Member] Visalia [Member] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Goodwill, Written off Related to Sale of Business Unit Goodwill, Written off Related to Sale of Business Unit Disposal Group, Including Discontinued Operation, Assets Disposal Group, Including Discontinued Operation, Assets Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Line of Credit Facility, Interest Rate at Period End Line of Credit Facility, Interest Rate at Period End Letters of Credit Outstanding, Amount Letters of Credit Outstanding, Amount Line of Credit Facility, Remaining Borrowing Capacity Line of Credit Facility, Remaining Borrowing Capacity Stock Repurchase Program, Authorized Amount Stock Repurchase Program, Authorized Amount Commitments and Contingencies Disclosure [Abstract] Schedule of Inventory, Current [Table Text Block] Schedule of Inventory, Current [Table Text Block] Compensation and Employee Benefit Plans [Text Block] Compensation and Employee Benefit Plans [Text Block] Risks and Uncertainties [Abstract] Controlling Shareholder [Text Block] Controlling Shareholder [Text Block] Controlling Shareholder [Text Block] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Goodwill [Line Items] Goodwill [Line Items] Goodwill Goodwill, Written off Related to Sale of Business Unit Goodwill, Purchase Accounting Adjustments Goodwill, Purchase Accounting Adjustments Goodwill Shareholders' Equity and Share-based Payments [Text Block] Shareholders' Equity and Share-based Payments [Text Block] ControllingShareholderOwnershipPercentage ControllingShareholderOwnershipPercentage Percentage of outstanding common stock owned by controlling shareholder Related Party Transaction, Purchases from Related Party Related Party Transaction, Purchases from Related Party 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] Trademarks and Trade Names [Member] Trademarks and Trade Names [Member] Technical Library Other Intangible Assets [Member] Customer Relationships [Member] Customer Relationships [Member] Noncompete Agreements [Member] Noncompete Agreements [Member] Backlog [Member] Order or Production Backlog [Member] Construction Contracts [Member] Customer Contracts [Member] Statistical Measurement [Axis] Statistical Measurement [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Asset, Useful Life Finite-Lived Intangible Asset, Useful Life Finite-Lived Intangible Assets, Gross Finite-Lived Intangible Assets, Gross Finite-Lived Intangible Assets, Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Intangible Assets, Net (Excluding Goodwill) Commitments and Contingencies Disclosure [Text Block] Commitments and Contingencies Disclosure [Text Block] Accrued Insurance, Current Accrued Insurance, Current Liability for Claims and Claims Adjustment Expense Liability for Claims and Claims Adjustment Expense Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Insurance Related [Member] Insurance Related [Member] Insurance Related Coverage Vendor Related [Member] Vendor Related [Member] Vendor Related Coverage Loss Contingencies [Line Items] Loss Contingencies [Line Items] Estimated cost of completion of bonded projects Estimatedcostofcompletionofbondedproject Estimated cost of completion of bonded projects