Debt	3 Months Ended
Mar. 31, 2016
Debt Disclosure [Abstract]
Debt	DEBT Revolving Credit Facility At March 31, 2016 and December 31, 2015, we along with Graybar Canada Limited, our Canadian operating subsidiary (“Graybar Canada”), had an unsecured, five-year, $550,000 revolving credit agreement maturing in June 2019 with Bank of America, N.A. and the other lenders named therein (the "Credit Agreement"), which includes a combined letter of credit sub-facility of up to $50,000, a U.S. swing line loan facility of up to $50,000, and a Canadian swing line loan facility of up to $20,000. The Credit Agreement includes a $100,000 sublimit (in U.S. or Canadian dollars) for borrowings by Graybar Canada and contains an accordion feature, which allows us to request increases to the aggregate borrowing commitments of up to $300,000. The Credit Agreement contains customary affirmative and negative covenants for credit facilities of this type, including limitations on us and our subsidiaries with respect to indebtedness, 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, restricted payments (subject to incurrence tests, with certain exceptions), as well as securitizations, factoring transactions, and transactions with sanctioned parties or in violation of certain U.S. or Canadian anti-corruption laws. There are also maximum leverage ratio and minimum interest coverage ratio financial covenants that we are subject to during the term of the Credit Agreement. We were in compliance with all these covenants as of March 31, 2016 and December 31, 2015. We had total letters of credit of $4,994 outstanding, of which none were issued under the Credit Agreement at March 31, 2016 and December 31, 2015. The letters of credit are used primarily to support certain workers' compensation insurance policies. There were $142,339 and $104,978 in short-term borrowings outstanding under the Credit Agreement at March 31, 2016 and December 31, 2015, respectively. Short-term borrowings outstanding during the three months ended March 31, 2016 and 2015 ranged from a minimum of $105,014 and $35,981 to a maximum of $159,596 and $130,878, respectively. At March 31, 2016, we had unused lines of credit under the Credit Agreement amounting to $407,661 available, compared to $445,022 at December 31, 2015. 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%). Private Placement Shelf Agreement At March 31, 2016 and December 31, 2015, we had an uncommitted $100,000 private placement Shelf Agreement with Prudential Investment Management, Inc. (the "Shelf Agreement"). The Shelf Agreement allows us to issue senior promissory notes to affiliates of Prudential at fixed rate terms to be agreed upon at the time of any issuance during a three year issuance period ending in September 2017. No notes had been issued under the Shelf Agreement as of March 31, 2016 and December 31, 2015. The Shelf Agreement contains various affirmative and negative covenants. We are also required to maintain certain financial ratios as defined in the agreement. We were in compliance with all covenants as of March 31, 2016 and December 31, 2015. In addition, we have agreed to a most favored lender clause which is designed to ensure that any notes issued under the Shelf Agreement in the future shall continue to be of equal ranking with our indebtedness under the Credit Agreement.

DEBT

Revolving Credit Facility

At March 31, 2016 and December 31, 2015, we along with Graybar Canada Limited, our Canadian operating subsidiary (“Graybar Canada”), had an unsecured, five-year, $550,000 revolving credit agreement maturing in June 2019 with Bank of America, N.A. and the other lenders named therein (the "Credit Agreement"), which includes a combined letter of credit sub-facility of up to $50,000, a U.S. swing line loan facility of up to $50,000, and a Canadian swing line loan facility of up to $20,000. The Credit Agreement includes a $100,000 sublimit (in U.S. or Canadian dollars) for borrowings by Graybar Canada and contains an accordion feature, which allows us to request increases to the aggregate borrowing commitments of up to $300,000.

The Credit Agreement contains customary affirmative and negative covenants for credit facilities of this type, including limitations on us and our subsidiaries with respect to indebtedness, 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, restricted payments (subject to incurrence tests, with certain exceptions), as well as securitizations, factoring transactions, and transactions with sanctioned parties or in violation of certain U.S. or Canadian anti-corruption laws. There are also maximum leverage ratio and minimum interest coverage ratio financial covenants that we are subject to during the term of the Credit Agreement. We were in compliance with all these covenants as of March 31, 2016 and December 31, 2015.

We had total letters of credit of $4,994 outstanding, of which none were issued under the Credit Agreement at March 31, 2016 and December 31, 2015. The letters of credit are used primarily to support certain workers' compensation insurance policies.

There were $142,339 and $104,978 in short-term borrowings outstanding under the Credit Agreement at March 31, 2016 and December 31, 2015, respectively.

Short-term borrowings outstanding during the three months ended March 31, 2016 and 2015 ranged from a minimum of $105,014 and $35,981 to a maximum of $159,596 and $130,878, respectively.

At March 31, 2016, we had unused lines of credit under the Credit Agreement amounting to $407,661 available, compared to $445,022 at December 31, 2015. 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%).

Private Placement Shelf Agreement

At March 31, 2016 and December 31, 2015, we had an uncommitted $100,000 private placement Shelf Agreement with Prudential Investment Management, Inc. (the "Shelf Agreement"). The Shelf Agreement allows us to issue senior promissory notes to affiliates of Prudential at fixed rate terms to be agreed upon at the time of any issuance during a three year issuance period ending in September 2017. No notes had been issued under the Shelf Agreement as of March 31, 2016 and December 31, 2015.

The Shelf Agreement contains various affirmative and negative covenants. We are also required to maintain certain financial ratios as defined in the agreement. We were in compliance with all covenants as of March 31, 2016 and December 31, 2015.

In addition, we have agreed to a most favored lender clause which is designed to ensure that any notes issued under the Shelf Agreement in the future shall continue to be of equal ranking with our indebtedness under the Credit Agreement.