Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net Income	$ 21,164	$ 17,723
Other Comprehensive Income
Foreign currency translation	(2,555)	657
Pension and postretirement benefits liability adjustment (net of tax of $(1,680) and $(1,974), respectively)	4,845	3,101
Total Other Comprehensive Income	2,290	3,758
Comprehensive Income	23,454	21,481
Less: comprehensive (loss) income attributable to noncontrolling interests, net of tax	(8)	108
Comprehensive Income attributable to Graybar Electric Company, Inc.	$ 23,462	$ 21,373