Document and Entity Information [Abstract] Document Type Document Type Document Quarterly Report Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Transition Report Entity File Number Entity Registrant Name Entity Registrant Name Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Address, Address Line One Entity Address, City or Town Entity Address, State or Province Entity Address, Postal Zip Code City Area Code Local Phone Number Entity Current Reporting Status Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Shell Company Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Current Fiscal Year End Date Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Central Index Key Entity Central Index Key Condensed Consolidated Statements Of Income [Abstract] Sales Revenue, Goods, Net Net Sales Cost of Goods and Services Sold Cost of merchandise sold Gross Profit Gross Margin Selling, General and Administrative Expense Selling, general and administrative expenses Total selling, general, and administrative expenses Depreciation, Depletion and Amortization Depreciation and amortization Depreciation and amortization Other Operating Income (Expense), Net Other operating income, net Operating Income (Loss) Income from Operations Other Nonoperating Expense Non-operating expenses, net Non-operating expenses, net Total non-operating expenses, net Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income before Provision for Income Taxes Income Tax Expense (Benefit) Provision for income taxes Tax benefit Total income tax provision Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Total reclassifications for the period, net of tax Net income Net Income Net Income Net Income (Loss) Attributable to Noncontrolling Interest Net income attributable to noncontrolling interests Net Income (Loss) Attributable to Parent Net Income attributable to Graybar Electric Company, Inc. Earnings Per Share, Basic Net Income attributable to Graybar Electric Company, Inc. per share of Common Stock Common Stock, Dividends, Per Share, Cash Paid Cash Dividends per share of Common Stock Weighted Average Number of Shares Outstanding, Basic Average Common Shares Outstanding Condensed Consolidated Statements Of Comprehensive Income [Abstract] Other Comprehensive Income (Loss), Net of Tax [Abstract] Other Comprehensive (Loss) Income Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Foreign currency translation Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Pension and postretirement benefits liability adjustments (net of tax of $(1.1), $(0.6), $(2.1) and $(1.2) respectively) Other Comprehensive Income (Loss), Net of Tax Other comprehensive income (loss) Total Other Comprehensive (Loss) Income Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive Income Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Less: Comprehensive income attributable to noncontrolling interests, net of tax Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive Income attributable to Graybar Electric Company, Inc. Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax Pension and postretirement benefits liability adjustments, tax Condensed Consolidated Balance Sheets [Abstract] Assets [Abstract] ASSETS Assets, Current [Abstract] Current Assets Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Accounts Receivable, Net, Current Trade receivables (less allowances of $15.8 and $14.0) Inventory, Net Merchandise inventory Other Assets, Current Other current assets Assets, Current Total Current Assets Property, Plant and Equipment, Net Property (less accumulated depreciation and amortization of $654.0 and $628.5) Net Property Operating Lease, Right-of-Use Asset Operating Lease Right-of-use Assets Goodwill Goodwill Intangible Assets, Net (Excluding Goodwill) Intangible Assets (less accumulated amortization of $101.5 and $88.0) Other Assets, Noncurrent Other Non-current Assets Assets Total Assets Liabilities and Equity [Abstract] LIABILITIES Liabilities, Current [Abstract] Current Liabilities Accounts Payable, Current Trade accounts payable Employee-related Liabilities, Current Accrued payroll and benefit costs Operating Lease, Liability, Current Current operating lease liabilities Deferred Revenue Deferred revenue Other Liabilities, Current Other current liabilities Liabilities, Current Total Current Liabilities Liability, Other Postretirement Defined Benefit Plan, Noncurrent Postretirement Benefits Liability Liability, Defined Benefit Pension Plan, Noncurrent Pension Liability Operating Lease, Liability, Noncurrent Non-current Operating Lease Liabilities Other Liabilities, Noncurrent Other Non-current Liabilities Liabilities Total Liabilities Capital Stock [Abstract] SHAREHOLDERS’ EQUITY Common Stock, Value, Outstanding Outstanding Common Stock Common Stock, Value, Subscriptions Advance Payments on Subscriptions to Common Stock Retained Earnings (Accumulated Deficit) Retained Earnings Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated Other Comprehensive Loss Stockholders' Equity Attributable to Parent Ending balance Beginning balance Total Graybar Electric Company, Inc. Shareholders’ Equity Stockholders' Equity Attributable to Noncontrolling Interest Noncontrolling Interests Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Balance Balance Total Shareholders’ Equity Liabilities and Equity Total Liabilities and Shareholders’ Equity Allowance for Doubtful Accounts Receivable, Current Trade receivables, allowances Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Accumulated depreciation and amortization Property, accumulated depreciation and amortization Finite-Lived Intangible Assets, Accumulated Amortization Accumulated Amortization Intangible assets, accumulated amortization Common Stock, Par or Stated Value Per Share Common stock, stated value per share Common Stock, Shares Authorized Authorized Number of shares of nonredeemable common stock issued to voting trustees. Common Stock, Shares, Issued, Voting Trustees Issued to voting trustees Number of shares of nonredeemable common stock issued to shareholders. Common Stock, Shares, Issued, Individuals Issued to shareholders Treasury Stock, Shares In treasury, at cost Common Stock, Shares, Outstanding Outstanding Common Stock Common Stock, Shares Issued Not Disclosed Common Stock, Shares Issued Not Disclosed Common stock, shares issued not disclosed Condensed Consolidated Statements Of Cash Flows [Abstract] Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Cash Flows from Operating Activities Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to cash provided by operating activities: Non-cash Operating Lease Expense Non-cash operating lease expense Deferred Income Tax Expense (Benefit) Deferred income taxes Gain (Loss) on Disposition of Property Plant Equipment Net losses (gains) on disposal of assets Asset Impairment Charges Losses on impairment of assets The earnings (loss) during the reporting period on invesment in employee deferred compensation trust. Earnings (Loss) On Invesment In Employee Deferred Compensation Trust Earnings on investment in employee deferred compensation trust Increase (Decrease) in Operating Capital [Abstract] Changes in assets and liabilities: Increase (Decrease) in Accounts Receivable Trade receivables Increase (Decrease) in Inventories Merchandise inventory Increase (Decrease) in Other Current Assets Other current assets Increase (Decrease) in Other Noncurrent Assets Other non-current assets Increase (Decrease) in Accounts Payable, Trade Trade accounts payable Increase (Decrease) in Employee Related Liabilities Accrued payroll and benefit costs Increase (Decrease) in Other Current Liabilities Other current liabilities Increase (Decrease) in Other Noncurrent Liabilities Non-current liabilities Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities Total adjustments to net income Net Cash Provided by (Used in) Operating Activities Net cash provided by operating activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash Flows from Investing Activities Proceeds from Sale of Property, Plant, and Equipment Proceeds from disposal of property Payments to Acquire Property, Plant, and Equipment Capital expenditures for property Proceeds from Insurance Settlement, Investing Activities Insurance proceeds from property claim Payments to Acquire Businesses, Net of Cash Acquired Amounts attributable to acquisitions Investment In Employee Deferred Compensation Trust Investment In Employee Deferred Compensation Trust Investment in employee deferred compensation trust Net Cash Provided by (Used in) Investing Activities Net cash used by investing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash Flows from Financing Activities Proceeds from (Repayments of) Short-term Debt Net decrease in short-term borrowings Payments Of Finance Arrangements Principal payments under finance leases Payment of deferred financing fees Payment of deferred financing fees Proceeds from Issuance of Common Stock Sales of common stock Payments for Repurchase of Common Stock Purchases of common stock Payments to Noncontrolling Interests Purchases of noncontrolling interests’ common stock Payments of Ordinary Dividends, Common Stock Dividends paid Cash dividends Payment for Contingent Consideration Liability, Financing Activities Contingent consideration paid Net Cash Provided by (Used in) Financing Activities Net cash used by financing activities Cash and Cash Equivalents, Period Increase (Decrease) Net (Decrease) Increase in Cash Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents Cash, End of Period Cash, Beginning of Year Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Non-cash Investing and Financing Activities Capital Lease Obligations Incurred Acquisitions of equipment under finance leases Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Acquisitions of assets under operating leases Condensed Consolidated Statements Of Changes in Shareholders’ Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock Including Additional Paid In Capital [Member] Common Stock [Member] Common Stock Subscribed, Unissued [Member] Common Stock Subscribed Unissued [Member] Common Stock Subscribed, Unissued [Member] Retained Earnings [Member] Retained Earnings [Member] Accumulated Other Comprehensive Income [Member] Accumulated Other Comprehensive Loss [Member] Noncontrolling Interest [Member] Noncontrolling Interests [Member] Statement [Line Items] Statement [Line Items] Stock Issued During Period, Value, New Issues Stock issued Stock Repurchased During Period, Value Stock purchased Advance Payments For Common Stock Subscription, Value Advance Payments For Common Stock Subscription, Value Advance payments Dividends Dividends declared Description Of The Business [Abstract] Nature of Operations [Text Block] Description Of The Business Summary Of Significant Accounting Policies [Abstract] Basis of Presentation and Significant Accounting Policies [Text Block] Summary Of Significant Accounting Policies Revenue [Abstract] Revenue from Contract with Customer [Text Block] Revenue Property [Abstract] Property, Plant and Equipment Disclosure [Text Block] Property Income Taxes [Abstract] Income Tax Disclosure [Text Block] Income Taxes Debt [Abstract] Debt Disclosure [Text Block] Debt Pension And Other Postretirement Benefits [Abstract] Pension and Other Postretirement Benefits Disclosure [Text Block] Pension And Other Postretirement Benefits Stockholders' Equity Note Disclosure [Text Block] Capital Stock Accumulated Other Comprehensive Loss [Abstract] Comprehensive Income (Loss) Note [Text Block] Accumulated Other Comprehensive Loss Commitments And Contingencies [Abstract] Commitments and Contingencies Disclosure [Text Block] Commitments And Contingencies Acquisitions [Abstract] Business Combination [Text Block] Acquisitions Intangible Assets [Abstract] Intangible Assets Disclosure [Text Block] Intangible Assets Basis of Accounting, Policy [Policy Text Block] Basis of Presentation Consolidation, Policy [Policy Text Block] Principles of Consolidation Reclassification, Comparability Adjustment [Policy Text Block] Reclassification New Accounting Pronouncements, Policy [Policy Text Block] New Accounting Standards Disaggregation of Revenue [Table Text Block] Disaggregation Of Revenue Property, Plant and Equipment [Table Text Block] Carrying Value Of Property Schedule of Net Benefit Costs [Table Text Block] Schedule Of Net Periodic Benefit Costs Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Reclassification Out Of Accumulated Other Comprehensive Income (Loss) Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] Changes In Accumulated Other Comprehensive Income (Loss) Business Combination, Recognized Asset Acquired and Liability Assumed [Table Text Block] Preliminary Purchase Price Allocation Finite-Lived Intangible Assets Amortization Expense [Table Text Block] Summary Of Intangible Assets Contract with Customer, Asset, after Allowance for Credit Loss Contract assets Contract with Customer, Liability Contract liabilities Disaggregation of Revenue [Table] Disaggregation of Revenue [Line Items] Concentration Risk, Percentage Total net sales Property, Plant and Equipment [Table] Property, Plant and Equipment [Line Items] Property, Plant and Equipment, Gross Total Property, at cost Effective Income Tax Rate Reconciliation, Percent Effective tax rate Line of Credit Facility [Table] Line of Credit Facility [Table] Debt Instrument [Axis] Debt Instrument Name [Domain] Debt Instrument, Name [Domain] Credit Agreement [Member] Credit Agreement [Member] Credit Agreement [Member] Prudential Private Placement Shelf Agreement Prudential Private Placement Shelf Agreement [Member] Prudential Private Placement Shelf Agreement [Member] MetLife Private Placement Shelf Agreement Met Life Private Placement Shelf Agreement [Member] MetLife Private Placement Shelf Agreement [Member] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Letter of Credit Sub Facility Member Letter Of Credit Sub Facility [Member] Letter of Credit Sub Facility [Member] Bridge Loan [Member] Swing-Line Loan [Member] Geographical [Axis] Segment Geographical [Domain] Segment, Geographical [Domain] U [S] United States [Member] C [A] Canada [Member] Legal Entity [Axis] Entity [Domain] Entity [Domain] Graybar Canada [Member] Graybar Canada [Member] Graybar Canada [Member] Statistical Measurement [Axis] Range [Member] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Debt Instrument, Term Debt instrument, term Line of Credit Facility, Maximum Borrowing Capacity Maximum borrowing capacity Line of Credit Facility, Expiration Date Expiration date Line of Credit Facility, Accordion Feature, Increase Limit Lineof Credit Facility, Accordion Feature, Increase Limit Accordion feature, increase limit Debt and Lease Obligation Total debt Long-Term Debt Long-term debt Short-term Debt Short-term borrowings Line of Credit Facility, Remaining Borrowing Capacity Remaining borrowing capacity Line of Credit Facility, Commitment Fee Percentage Credit agreement commitment fee percentage Interest Income (Expense), Net Interest income (expense), net Private Placement Issuance Period Private Placement Issuance Period Issuance period Private Placement After Issuance Successive Period Private Placement After Issuance Successive Period Successive issuance period Debt Instrument, Face Amount Notes issued face amount Letters of Credit Outstanding, Amount Letters of credit outstanding Schedule of Defined Benefit Plans Disclosures [Table] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Pension Plans Defined Benefit [Member] Pension Benefits [Member] Other Postretirement Benefit Plans Defined Benefit [Member] Postretirement Benefits [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan, Matching Eligibility Requirement, Term Of Service. Defined Benefit Plan Duration Of Service Required term of service to be eligible for plan match Deferred Compensation Plan Assets Plan assets Defined Benefit Plan, Plan Assets, Contributions by Employer Employer contributions Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year Expected employer contributions remainder of year Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Defined Benefit Plan, Service Cost Service cost Defined Benefit Plan, Interest Cost Interest cost Defined Benefit Plan, Expected Return (Loss) on Plan Assets Expected return on plan assets Defined Benefit Plan, Amortization of Gain (Loss) Amortization of net actuarial loss Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Net periodic benefit cost Stockholders' Equity Note, Percent of Entity Owned by Current and Retired Employees Stockholders' Equity Note, Percentof Entity Ownedby Currentand Retired Employees Percent of stock owned by active and retired employees The percentage of common stock held in the Voting Trust Stockholders Equity Note, Percentof Entity Heldin Voting Trust Percent of shares held in voting trust Preferred Stock, Shares Authorized Preferred stock shares authorized Preferred Stock, Par or Stated Value Per Share Preferred stock par or stated value per share (USD per share) Preferred Stock, Shares Outstanding Preferred stock outstanding (in shares) Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification Out Of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification Out Of Accumulated Other Comprehensive Income [Member] Amortization Of Pension And Other Postretirement Benefits Items [Member] Accumulated Defined Benefit Plans Adjustment Net Unamortized Gain Loss [Member] Actuarial Losses Recognized [Member] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Translation Adjustment [Member] Foreign Currency [Member] Accumulated Defined Benefit Plans Adjustment [Member] Pension and Other Postretirement Benefits [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward] Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward] OCI, before Reclassifications, Net of Tax, Attributable to Parent Other comprehensive (loss) income before reclassifications Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Amounts reclassified from accumulated other comprehensive income (net of tax) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Net current-period other comprehensive (loss) income Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax Amounts reclassified from accumulated other comprehensive loss, tax Commitments And Contingencies [Table] Commitments And Contingencies [Table] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Other Current Liabilities [Member] Other Current Liabilities [Member] Other Noncurrent Liabilities [Member] Other Noncurrent Liabilities [Member] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Insurance Settlements Receivable, Current Insurance receivables current Insurance Settlements Receivable, Noncurrent Insurance receivables non-current Liability for Asbestos and Environmental Claims, Gross Liability related to asbestos claims and related insurance receivables Business Combination [Table] Business Combination [Line Items] Business Combination, Number of Businesses Acquired Number of businesses acquired Business Combination, Consideration Transferred Acquisition preliminary purchase price Business Combination, Recognized Asset Acquired, Asset, Current Current Assets Business Combination, Recognized Asset Acquired, Property, Plant, and Equipment Property Business Combination, Recognized Asset Acquired, Identifiable Intangible Asset, Excluding Goodwill Intangible Assets Business Combination, Recognized Asset Acquired, Other Asset, Noncurrent Other Non-current Assets Business Combination, Recognized Liability Assumed, Liability, Current Current Liabilities Business Combination, Recognized Asset Acquired to Liability Assumed, Excess (Less), and Goodwill Total combined preliminary purchase price Intangible Asset, Finite-Lived [Table] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets, Gross Gross Carrying Amount Net Carrying Amount Net Carrying Amount Insider Trading Arrangements [Line Items] Rule 10b5-1 Arrangement Adopted [Flag] Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Non-Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Terminated [Flag] Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Non-Rule 10b5-1 Arrangement Terminated Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Revenue From Contract With Customer [Member] Revenue from Contract with Customer [Member] Product and Service [Axis] Products And Services [Domain] Products and Services [Domain] Construction [Member] Construction [Member] Commercial Institutional Government [Member] Commercial Institutional Government [Member] CIG [Member] Industrialand Utility [Member] Industrialand Utility [Member] Industrial & Utility [Member] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Product Concentration Risk [Member] Product Concentration Risk [Member] Long-Lived Tangible Asset [Axis] Property Plant And Equipment Type [Domain] Long-Lived Tangible Asset [Domain] Land [Member] Land [Member] Building [Member] Building [Member] Furniture And Fixtures [Member] Furniture and Fixtures [Member] Software And Software Development Costs [Member] Software [Member] Finance Leases [Member] Finance Leases [Member] Finance Leases [Member] Business Combination [Axis] Business Acquisition Acquiree [Domain] Business Combination [Domain] Series Of Individually Immaterial Business Acquisitions [Member] Series of Individually Immaterial Business Combinations [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite Lived Intangible Assets Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Customer Relationships [Member] Customer Relationships [Member] Trade Names [Member] Trade Name [Member] Noncompete Agreements [Member] Non-Compete Agreements [Member] Other Intangible Assets [Member] Other Intangible Assets [Member]