v3.26.1
Background and Summary of Significant Accounting Policies - Additional Information (Detail)
 12 Months Ended
Mar. 31, 2026
USD ($)
customer
segment
Mar. 31, 2025
USD ($)
Mar. 31, 2024
USD ($)
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]      
Number of reportable segments | segment 2    
Impairment charges for intangible assets $ 0 $ 0  
Advertising costs 14,300,000 10,600,000 $ 10,200,000
Life, accidental death and dismemberment and medical coverage 63,300,000 60,000,000.0 53,300,000
Self insurance plan employees contribution 13,500,000 13,800,000 13,000,000.0
Total claims expense, self insurance $ 5,900,000 $ 4,700,000 $ 4,900,000
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 10.40% 19.10%  
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 25.80% 27.00% 25.80%
Core & Main | Accounts Receivable | Customer Concentration Risk      
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]      
Concentration risk percentage 10.40%    
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 1,000,000    
Total claims expense, self insurance 2,900,000 $ 3,700,000 $ 3,100,000
Shipping and Handling      
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]      
Shipping costs $ 369,200,000 $ 340,800,000 $ 284,600,000
Minimum      
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]      
Capitalized software development costs estimated useful lives 2 years    
Claims per incident $ 500,000    
Maximum      
Schedule Of Organization And Summary Of Significant Accounting Policies [Line Items]      
Capitalized software development costs estimated useful lives 10 years