Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Net Sales	$ 6,385,032	$ 6,110,299	$ 5,978,861
Cost of merchandise sold	(5,176,654)	(4,955,554)	(4,860,314)
Gross Margin	1,208,378	1,154,745	1,118,547
Selling, general and administrative expenses	(1,008,744)	(965,134)	(935,132)
Depreciation and amortization	(47,852)	(43,242)	(39,151)
Other income, net	5,347	8,199	3,918
Income from Operations	157,129	154,568	148,182
Interest expense, net	(3,630)	(2,227)	(1,371)
Income before Provision for Income Taxes	153,499	152,341	146,811
Provision for income taxes	(60,186)	(61,009)	(59,125)
Net Income	93,313	91,332	87,686
Net income attributable to noncontrolling interests	(234)	(264)	(258)
Net Income attributable to Graybar Electric Company, Inc.	$ 93,079	$ 91,068	$ 87,428
Net Income attributable to Graybar Electric Company, Inc. per share of Common Stock (usd per share)	$ 5.35	$ 5.30	$ 5.13