Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Gross Sales	$ 1,590,576	$ 1,576,376	$ 4,566,880	$ 4,418,354
Cash discounts	(6,690)	(6,619)	(19,208)	(18,422)
Net Sales	1,583,886	1,569,757	4,547,672	4,399,932
Cost of merchandise sold	(1,280,928)	(1,275,222)	(3,692,343)	(3,573,998)
Gross Margin	302,958	294,535	855,329	825,934
Selling, general and administrative expenses	(244,672)	(233,773)	(717,648)	(678,647)
Depreciation and amortization	(10,960)	(9,786)	(32,082)	(29,140)
Other income, net	1,187	739	6,746	2,897
Income from Operations	48,513	51,715	112,345	121,044
Interest expense, net	(685)	(364)	(1,895)	(1,122)
Income before Provision for Income Taxes	47,828	51,351	110,450	119,922
Provision for income taxes	(19,431)	(20,815)	(44,414)	(48,929)
Net Income	28,397	30,536	66,036	70,993
Less: Net income attributable to noncontrolling interests	(86)	(72)	(177)	(164)
Net Income attributable to Graybar Electric Company, Inc.	$ 28,311	$ 30,464	$ 65,859	$ 70,829
Net Income per share of Common Stock (in dollars per share)	$ 1.77	$ 1.93	$ 4.12	$ 4.47
Cash Dividends per share of Common Stock (in dollars per share)	$ 0.30	$ 0.30	$ 0.90	$ 0.90
Average Common Shares Outstanding (Shares)	15,942	15,799	15,980	15,861