Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Gross Sales		$ 1,637,514	$ 1,576,441	$ 3,109,208	$ 2,976,304
Cash discounts		(6,993)	(6,433)	(13,207)	(12,518)
Net Sales		1,630,521	1,570,008	3,096,001	2,963,786
Cost of merchandise sold		(1,324,922)	(1,276,663)	(2,510,755)	(2,411,415)
Gross Margin		305,599	293,345	585,246	552,371
Selling, general and administrative expenses		(250,565)	(240,909)	(495,297)	(472,976)
Depreciation and amortization		(11,564)	(10,813)	(22,875)	(21,122)
Other income, net		517	1,217	2,809	5,559
Income from Operations		43,987	42,840	69,883	63,832
Interest expense, net		(763)	(697)	(1,420)	(1,210)
Income before Provision for Income Taxes		43,224	42,143	68,463	62,622
Provision for income taxes		(17,530)	(16,998)	(27,672)	(24,983)
Net Income		25,694	25,145	40,791	37,639
Less: Net income attributable to noncontrolling interests		(59)	(57)	(111)	(91)
Net Income attributable to Graybar Electric Company, Inc.		$ 25,635	$ 25,088	$ 40,680	$ 37,548
Net Income per share of Common Stock (in dollars per share)	[1]	$ 1.55	$ 1.53	$ 2.46	$ 2.29
Cash Dividends per share of Common Stock (in dollars per share)		$ 0.30	$ 0.30	$ 0.60	$ 0.60
Average Common Shares Outstanding (Shares)	[1]	16,569	16,386	16,555	16,398

[1] (A)Adjusted for the declaration of a 2.5% stock dividend in 2015, shares related to which were issued in February 2016. Prior to the adjustment, the average common shares outstanding were 15,987 and 15,998 for the three and six months ended June 30, 2015, respectively.