Condensed Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
GrossRevenues	$ 1,957.1	$ 1,840.4	$ 3,743.2	$ 3,485.4
SalesDiscounts	9.1	8.1	17.4	15.4
Revenues	1,948.0	1,832.3	3,725.8	3,470.0
Cost of merchandise sold	(1,580.3)	(1,481.1)	(3,019.4)	(2,807.4)
Gross Margin	367.7	351.2	706.4	662.6
Selling, general and administrative expenses	(284.5)	(270.8)	(558.0)	(534.1)
Depreciation and amortization	(12.6)	(12.3)	(25.1)	(24.4)
Other income, net	0.5	0.6	1.8	1.4
Income from Operations	71.1	68.7	125.1	105.5
Non-operating expenses	(6.3)	(7.5)	(12.9)	(15.0)
Income before Provision for Income Taxes	64.8	61.2	112.2	90.5
Provision for income taxes	(17.8)	(16.6)	(30.8)	(24.7)
Net Income	47.0	44.6	81.4	65.8
Less: Net income attributable to noncontrolling interests	0.0	(0.1)	(0.1)	(0.2)
Net Income attributable to Graybar Electric Company, Inc.	$ 47.0	$ 44.5	$ 81.3	$ 65.6
Net Income per share of Common Stock (in dollars per share)	$ 2.18	$ 2.07	$ 3.77	$ 3.05
Cash Dividends per share of Common Stock (in dollars per share)	$ 0.30	$ 0.30	$ 0.60	$ 0.60
Average Common Shares Outstanding (Shares)	21.5	21.5	21.6	21.5