Condensed Consolidated Statements Of Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Condensed Consolidated Statements Of Income [Abstract]
Net Sales	$ 3,298.8	$ 2,979.5	$ 9,618.5	$ 8,717.5
Cost of merchandise sold	(2,660.0)	(2,382.3)	(7,764.9)	(6,986.5)
Gross Margin	638.8	597.2	1,853.6	1,731.0
Selling, general and administrative expenses	(449.8)	(426.8)	(1,305.2)	(1,235.8)
Depreciation and amortization	(21.9)	(20.2)	(64.5)	(59.9)
Other operating (expense) income, net	(6.8)	1.1	1.6	8.7
Income from Operations	160.3	151.3	485.5	444.0
Non-operating expenses, net	(0.3)	(0.8)	(3.2)	(2.9)
Income before Provision for Income Taxes	160.0	150.5	482.3	441.1
Provision for income taxes	(40.4)	(40.0)	(123.2)	(114.5)
Net Income	119.6	110.5	359.1	326.6
Net income attributable to noncontrolling interests	(0.3)	(0.3)	(0.8)	(0.8)
Net Income attributable to Graybar Electric Company, Inc.	$ 119.3	$ 110.2	$ 358.3	$ 325.8
Net Income attributable to Graybar Electric Company, Inc. per share of Common Stock	$ 3.68	$ 3.42	$ 11.04	$ 10.08
Cash Dividends per share of Common Stock	$ 0.30	$ 0.30	$ 0.90	$ 0.90
Average Common Shares Outstanding	32.4	32.2	32.5	32.3