Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net Income	$ 29,554	$ 30,196	$ 80,678	$ 70,987
Other Comprehensive Income
Foreign currency translation	3,616	(1,148)	6,550	4,012
Pension and postretirement benefits liability adjustment (net of tax of $(1,997), $(1,762), $(5,990), and $(5,286), respectively)	3,136	2,767	9,408	8,301
Total Other Comprehensive Income	6,752	1,619	15,958	12,313
Comprehensive Income	36,306	31,815	96,636	83,300
Less: Comprehensive income attributable to noncontrolling interests, net of tax	209	25	457	387
Comprehensive Income attributable to Graybar Electric Company, Inc.	$ 36,097	$ 31,790	$ 96,179	$ 82,913