Entity Tax Identification Number Entity Tax Identification Number Maximum Maximum [Member] Legal Entity [Axis] Legal Entity [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] EBP, Description of Plan [Table] EBP, Description of Plan [Table] Mutual funds Fidelity Total Market Index Fund Mutual Fund [Member] EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Related Party and Party-in-Interest Transactions [Table] Total deductions EBP, Change in Net Asset Available for Benefit, Decrease Maximum borrowing, amount EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount Fair Value Measurements EBP, Investment, Fair Value and NAV [Text Block] Minimum borrowing, amount EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount Total investments EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value Money market fund Money Market Funds [Member] (Level 1) Fair Value, Inputs, Level 1 [Member] EBP, Investment, Fair Value and NAV [Abstract] Assets: EBP, Asset [Abstract] Statistical Measurement [Axis] Statistical Measurement [Axis] Additions: EBP, Change in Net Asset Available for Benefit, Increase [Abstract] EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Statement of Change in Net Asset Available for Benefit [Table] Payment of Benefits EBP, Payment to Participant [Policy Text Block] Amendment Flag Amendment Flag Maximum annual compensation to total compensation, percentage EBP, Participant Contribution, Maximum Contribution to Eligible Compensation, Percentage EBP, Participant Contribution, Maximum Contribution to Eligible Compensation, Percentage Participant EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution Basis of Accounting EBP, Basis of Accounting [Policy Text Block] EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Table] Class action settlement proceeds EBP, Change in Net Asset Available for Benefit, Increase from Class Action Settlement Proceeds EBP, Change in Net Asset Available for Benefit, Increase from Class Action Settlement Proceeds Number of shares (in shares) EBP, Investment, Number of Shares EBP, Description of Plan and Accounting Change [Abstract] EBP, Investment, Fair Value and NAV EBP, Investment, Fair Value and NAV [Table Text Block] EBP, Employer Contribution, Account [Domain] EBP, Employer Contribution, Account [Domain] EBP, Employer Contribution, Account [Domain] Investments [Domain] Investments [Domain] Use of Estimates EBP, Use of Estimate [Policy Text Block] Schedule H, Line 4i – Schedule of Assets (Held At End of Year) EBP, Schedule of Asset Held for Investment [Text Block] Cover [Abstract] Rollover limit EBP, Rollover Limit EBP, Rollover Limit Concentration of Investments EBP, Risk and Uncertainty [Text Block] Employer EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash EBP, Risk and Uncertainty EBP, Risk and Uncertainty [Table Text Block] Minimum Minimum [Member] Interest income on notes receivable from participants EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Investment Type [Axis] Investment Type [Axis] Total contributions EBP, Change in Net Asset Available for Benefit, Increase from Contribution NiSource Inc. common stock NiSource Stock Fund, Common Stock [Member] NiSource Stock Fund, Common Stock Net appreciation in fair value of investments EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment Dividends and interest EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment Maximum term for repayment deferral EBP, Note Receivable From Participant, Account, Maximum Term For Repayment Deferral EBP, Note Receivable From Participant, Account, Maximum Term For Repayment Deferral 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] Account Balance II Account Balance II [Member] Account Balance II 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] NiSource Inc. common stock EBP, Employer, Common Stock [Member] Annual Next Gen Employer Contribution, percentage EBP, Employer Contribution, Annual Contribution, Percentage EBP, Employer Contribution, Annual Contribution, Percentage EBP, Schedule of Asset Held for Investment [Abstract] EBP, Accounting Policy [Table] EBP, Accounting Policy [Table] Total additions EBP, Change in Net Asset Available for Benefit, Increase Investment income: EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment [Abstract] Investment, Identifier [Axis] Investment, Identifier [Axis] Administrative expenses, net EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Total Assets (Held at End of Year) EBP, Asset Held for Investment Risk and Uncertainties EBP, Risk and Uncertainty [Policy Text Block] Document Information [Line Items] Document Information [Line Items] EBP, Risk and Uncertainty [Line Items] EBP, Risk and Uncertainty [Line Items] EBP, Employer Contribution, Account [Axis] EBP, Employer Contribution, Account [Axis] EBP, Employer Contribution, Account EBP, Risk and Uncertainty [Table] EBP, Risk and Uncertainty [Table] Money market government portfolio EBP, NiSource Stock Fund, Money Market Funds Government Portfolio [Member] EBP, NiSource Stock Fund, Money Market Funds Government Portfolio Participant compensation matched, percentage EBP, Employer Contribution, Participant Compensation Matched, Percentage EBP, Statement of Change in Net Asset Available for Benefit [Abstract] (Level 2) Fair Value, Inputs, Level 2 [Member] Spartan Total Market Index Pool Market Index Pool [Member] Market Index Pool Primary residence, maximum borrowing term EBP, Note Receivable From Participant, Account, Primary Residence, Maximum Borrowing Term EBP, Note Receivable From Participant, Account, Primary Residence, Maximum Borrowing Term EBP, Tax Status [Table] EBP, Tax Status [Table] Net increase EBP, Change in Net Asset Available for Benefit, Increase (Decrease) Exempt Party-In-Interest Transactions EBP, Related Party and Party-in-Interest Transactions [Text Block] EBP, Related Party and Party-in-Interest Transactions [Abstract] EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract] Discretionary contribution EBP, Employer Contribution, Receivable Automatic deferral rate EBP, Participant Contribution, Automatic, Deferral Rate Investments - at fair value: EBP, Investment, Fair Value [Abstract] Dividend income EBP, Change in Net Asset Available for Benefit, Increase from Dividend Income on Investment Benefits paid to participants EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant 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] EBP, Statement of Net Asset Available for Benefit [Abstract] EBP, Accounting Policy [Line Items] EBP, Accounting Policy [Line Items] EBP, Tax Status [Abstract] NIPSCO Union Pension Plan NIPSCO Union Pension Plan [Member] NIPSCO Union Pension Plan NiSource Stock Fund EBP, Employer, Common Stock Fund [Member] NiSource Stock Fund EBP, Common Stock [Policy Text Block] EBP, Common Stock EBP 005 EBP 005 [Member] EBP 005 Maximum pre-tax, catch-up and Roth basis annual compensation to total compensation, percentage EBP, Participant Contribution, Pre-Tax, Catch-Up and Roth, Maximum Contribution to Eligible Compensation, Percentage EBP, Participant Contribution, Pre-Tax, Catch-Up and Roth, Maximum Contribution to Eligible Compensation, Percentage Administrative Expenses EBP, Expense [Policy Text Block] Various plan participants EBP, Asset Held for Investment, Participant Loan, after Deemed Distribution Investments EBP, Investment [Policy Text Block] Total Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Document Type Document Type Plan Termination EBP, Plan Termination [Text Block] Entity Central Index Key Entity Central Index Key General loan, maximum borrowing term EBP, Note Receivable From Participant, General Loan, Maximum Borrowing Term EBP, Note Receivable From Participant, General Loan, Maximum Borrowing Term Number of customers EBP, Number of Customers EBP, Number of Customers Participant loan, interest rate EBP, Asset Held for Investment, Participant Loan, Interest Rate Amount rebated back to participants' accounts EBP, Forfeited Nonvested Account, Reallocated to Participant Common collective trusts Common Collective Trust [Member] EBP, Risk and Uncertainty [Abstract] EBP, Tax Status [Line Items] EBP, Tax Status [Line Items] Deductions: EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] Maximum after-tax annual compensation to total compensation, percentage EBP, Participant Contribution, After-Tax, Maximum Contribution to Eligible Compensation, Percentage EBP, Participant Contribution, After-Tax, Maximum Contribution to Eligible Compensation, Percentage Account Balance I Account Balance I [Member] Account Balance I Notes receivable from participants EBP, Note Receivable from Participant Involuntary cash-out limit EBP, Involuntary Cash-out Limit EBP, Involuntary Cash-out Limit Number of states the entity operates in EBP, Number of States the Entity Operates In EBP, Number of States the Entity Operates In 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 Total assets EBP, Risk and Uncertainty, Concentration of Investment at Fair Value to Net Assets, Amount Recently Adopted Legislation and Regulations EBP, New Legislation [Policy Text Block] EBP, New Legislation Cost EBP, Investment, Excluding Plan Interest in Master Trust, Cost Non-Eligible Pension Plans Non-Eligible Pension Plans [Member] Non-Eligible Pension Plans Subsequent Events EBP, Subsequent Event [Policy Text Block] Tax Status EBP, Tax Status [Text Block] Maximum borrowing, to total account, percentage EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage Percent of total investments EBP, Risk and Uncertainty, Concentration of Investment at Fair Value to Total Investments, Percentage Document Information [Table] Document Information [Table] Notes Receivable from Participants EBP, Note Receivable from Participant [Policy Text Block] Net investment income EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment EBP, Related Party and Party-in-Interest Transactions [Line Items] EBP, Related Party and Party-in-Interest Transactions [Line Items] (Level 3) Fair Value, Inputs, Level 3 [Member] Maximum number of loans EBP, Note Receivable From Participant, Maximum Number of Loans EBP, Note Receivable From Participant, Maximum Number of Loans Fidelity Growth Company Commingled Pool Commingled Pool [Member] Commingled Pool 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] Contributions: EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Matching percentage EBP, Employer Contribution, Matching Percentage 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]