Debt	3 Months Ended
	Mar. 31, 2022
Debt [Abstract]
Debt	5. DEBT Revolving Credit Facility At March 31, 2022, and December 31, 2021, we, along with Graybar Canada Limited, our Canadian operating subsidiary ("Graybar Canada"), had an unsecured, five-year, $750.0 million committed revolving credit agreement maturing in August 2026 with Bank of America, N.A. and the other lenders named therein (the "Amended Credit Agreement"), which includes a combined letter of credit sub-facility of up to $25.0 million, a U.S. swing-line loan facility of up to $75.0 million, and a Canadian swing-line loan facility of up to $20.0 million. The Amended Credit Agreement includes a $100.0 million sublimit (in U.S. or Canadian dollars) for borrowings by Graybar Canada.  Our borrowing availability under the facility is reduced by the amount of borrowings by Graybar Canada, but we may use the sublimit amount to increase our borrowings, to the extent available. If we were to use available borrowings under the Amended Credit Agreement that included the sublimit amount, then Graybar Canada’s available capacity would be reduced by our use of such amount. The Amended Credit Agreement contains an accordion feature, which allows us to request increases in the aggregate borrowing commitments of up to $375.0 million. The Amended Credit Agreement contains customary affirmative and negative covenants for credit facilities of this type, including limitations on us and all but certain of our subsidiaries with respect to indebtedness (with specified, limited exceptions), liens, changes in the nature of our business, investments, mergers and acquisitions, issuance of equity securities, dispositions of assets and dissolution of certain subsidiaries, transactions with affiliates, as well as securitizations, factoring transactions, and transactions with sanctioned parties or in violation of certain US or Canadian anti-corruption and anti-money laundering laws. There are also maximum leverage ratio and minimum interest coverage ratio financial covenants to which we will be subject during the term of the Amended Credit Agreement. We were in compliance with all covenants under the Amended Credit Agreement as of March 31, 2022 and December 31, 2021. There were $70.0 million and $124.2 million in short-term borrowings under the Amended Credit Agreement, respectively, as of March 31, 2022 and December 31, 2021. Short-term borrowings outstanding during the three months ended March 31, 2022 ranged from a minimum of $33.1 million to a maximum of $173.1 million. Short-term borrowings outstanding during the three months ended March 31, 2021 ranged from a minimum of no short-term borrowings to a maximum of $50.0 million. At March 31, 2022, we had unused lines of credit under the Amended Credit Agreement amounting to $679.6 million available, compared to $625.4 million at December 31, 2021. These lines are available to meet our short-term cash requirements and are subject to annual fees of up to 40 basis points (0.40%). Interest expense, net was $0.8 million and $0.2 million for the three months ended March 31, 2022 and 2021, respectively. Private Placement Shelf Agreements We have an uncommitted, unsecured $100.0 million private placement shelf agreement (the “Prudential Shelf Agreement”) with PGIM, Inc., which is expected to allow us to issue senior promissory notes to affiliates of PGIM, Inc. at fixed rate terms to be agreed upon at the time of any issuance during a three-year issuance period ending in August 2023. We also have an uncommitted, unsecured $150.0 million private placement shelf agreement (the "MetLife Shelf Agreement") with MetLife Investment Management, LLC (formerly known as MetLife Investment Advisors, LLC), and MetLife Investment Management Limited (collectively, “MetLife”) and each other MetLife affiliate that becomes a party to the agreement. The MetLife Shelf Agreement is expected to allow us to issue senior promissory notes to MetLife at fixed or floating rate economic terms to be agreed upon at the time of issuance during a three-year issuance period ending in June 2024. We remain obligated under a most favored lender clause which is designed to ensure that any notes in the future under the Prudential Shelf Agreement and MetLife Shelf Agreement will continue to be of equal ranking with indebtedness under our Amended Credit Agreement. No notes have been issued under either the Prudential Shelf Agreement or the MetLife Shelf Agreement as of March 31, 2022 and December 31, 2021. Each shelf agreement contains representations and warranties of the Company and the applicable lender, events of default and affirmative and negative covenants, customary for agreements of this type.  These covenants are substantially similar to those contained in the Amended Credit Agreement, subject to a number of exceptions and qualifications set forth in the applicable shelf agreement. All outstanding obligations of Graybar under one or both of these agreements may be declared immediately due and payable upon the occurrence of an event of default. We were in compliance with all covenants under the Prudential Shelf Agreement and the MetLife Shelf Agreement as of March 31, 2022 and December 31, 2021. Letters of Credit We had total letters of credit of $6.1 million outstanding at both March 31, 2022 and December 31, 2021, of which $0.4 million were issued under the Amended Credit Agreement. The letters of credit are issued primarily to support certain workers' compensation insurance policies.