Background and Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Mar. 31, 2023 USD ($) customer segment	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments | segment	3
Impairment charges for goodwill	$ 0	$ 0
Impairment charges for intangible assets	0	0
Advertising costs	8,500,000	6,000,000	$ 4,100,000
Life, accidental death and dismemberment and medical coverage	52,100,000	45,600,000	42,400,000
Self insurance plan employees contribution	12,400,000	10,700,000	8,500,000
Total claims expense, self insurance	$ 4,900,000	$ 4,100,000	$ 3,000,000
Minimum likelihood percentage of tax benefit to be realized upon settlement	50.00%
Ferguson Enterprises | Accounts Receivable | Customer Concentration Risk
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage	20.00%	16.40%
Ferguson Enterprises and Core and Main | Sales Revenue, Net
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Number of customers in the customer base | customer	16,000
Ferguson Enterprises and Core and Main | Sales Revenue, Net | Customer Concentration Risk
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage	25.50%	24.20%	22.80%
Other General Insurance Programs
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Claims per occurrence for general liability	$ 500,000
Claims per occurrence for automobile	800,000
Total claims expense, self insurance	3,100,000	$ 3,200,000	$ 1,700,000
Shipping and Handling
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Shipping costs	$ 274,500,000	$ 242,000,000	$ 174,200,000
Minimum
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Capitalized software development costs estimated useful lives	2 years
Claims per incident	$ 300,000
Maximum
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]
Capitalized software development costs estimated useful lives	10 years