Debt (Narrative) (Details) - USD ($)		3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 20, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Line of Credit Facility [Line Items]
Short-term borrowings		$ 13,000,000.0		$ 13,000,000.0		$ 31,600,000
Interest expense, net		1,500,000	$ 700,000	2,400,000	$ 1,500,000
Letters of credit outstanding		7,700,000		7,700,000		7,800,000
Minimum
Line of Credit Facility [Line Items]
Short-term borrowings		0	33,100,000	0	33,100,000
Maximum
Line of Credit Facility [Line Items]
Short-term borrowings		175,000,000.0	$ 173,100,000	175,000,000.0	$ 173,100,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Short-term borrowings						30,000,000.0
Amended Credit Agreement
Line of Credit Facility [Line Items]
Remaining borrowing capacity		735,100,000		$ 735,100,000		718,100,000
Credit agreement commitment fee percentage				0.40%
Letters of credit outstanding		1,900,000		$ 1,900,000		1,900,000
Prudential Private Placement Shelf Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity		100,000,000.0		$ 100,000,000.0
Debt maturity date				Aug. 01, 2023
Issuance period				3 years
Prudential Private Placement Shelf Agreement | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 200,000,000.0
Debt maturity date	Aug. 01, 2026
MetLife Private Placement Shelf Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity		150,000,000.0		$ 150,000,000.0
Debt maturity date				Jun. 01, 2024
Issuance period				3 years
Prudential Shelf Agreement Or MetLife Shelf Agreement
Line of Credit Facility [Line Items]
Maximum borrowing capacity		100,000,000.0		$ 100,000,000.0
Debt maturity date	Aug. 01, 2026
Notes issued face amount		$ 0		$ 0		0
Prudential Shelf Agreement Or MetLife Shelf Agreement | Subsequent Event [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 200,000,000.0
Line of credit | Amended Credit Agreement | Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity						750,000,000.0
Accordion feature, increase limit						$ 375,000,000.0
Expiration date						Aug. 01, 2026
Debt instrument, term						5 years
Line of credit | Amended Credit Agreement | Letter of Credit Sub-Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity						$ 25,000,000.0
Line of credit | Amended Credit Agreement | Bridge Loan | Graybar Canada
Line of Credit Facility [Line Items]
Maximum borrowing capacity						100,000,000.0
Line of credit | Amended Credit Agreement | Bridge Loan | UNITED STATES
Line of Credit Facility [Line Items]
Maximum borrowing capacity						75,000,000.0
Line of credit | Amended Credit Agreement | Bridge Loan | CANADA
Line of Credit Facility [Line Items]
Maximum borrowing capacity						$ 20,000,000.0