v3.26.1
Significant Accounting Policies - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
May 17, 2022
Significant Accounting Policies [Line Items]        
Allowance for doubtful accounts $ 6,300 $ 6,400    
Bad debt expense 800 200 $ 300  
Write-offs of accounts receivable 900 600 600  
Depreciable assets $ 149,500 147,600 139,500  
Basis of valuation Property, Plant, and Equipment are stated at cost.      
Property, Plant and Equipment, Depreciation Methods1 straight-line basis over the estimated useful lives      
Goodwill impairment more likely than not a likelihood as greater percentage of fair value of reportable unit exceeds its carrying value 50.00%      
Intangible Assets, Amortization Expense $ 10,300 $ 8,400 $ 7,900  
Amortization expense, expected, for fiscal year 2027 10,200      
Amortization expense, expected, for fiscal year 2028 10,000      
Amortization expense, expected, for fiscal year 2029 9,800      
Amortization expense, expected, for fiscal year 2030 9,800      
Amortization expense, expected, for fiscal year 2031 $ 9,800      
Number of additional shares authorized to be repurchased       7,500,000
Repurchase of shares 1,739,625 1,214,173 1,863,534  
Shares repurchased average price $ 219.48 $ 245.67 $ 184.2  
Stock repurchase remaining number of shares authorized to be repurchased 2,929,872      
Freight expense $ 1,656,115 $ 1,587,371 $ 1,573,976  
Accumulated other comprehensive loss 4,404 3,125    
Net of income taxes for accumulated other comprehensive loss 1,400      
Maintenance and repair expenses $ 244,200 $ 248,400 $ 220,100  
Stock options excluded from computation of diluted earnings per share 31,222 4,404 16,609  
Stock options, average exercise price per share $ 219.14 $ 240.32 $ 133.91  
Freight [Member]        
Significant Accounting Policies [Line Items]        
Freight expense $ 215,100 $ 211,200 $ 215,300  
Minimum [Member]        
Significant Accounting Policies [Line Items]        
Long term supply agreements term of termination notice period 2 years      
Revenue from contract with customer collection terms 30 days      
Maximum [Member]        
Significant Accounting Policies [Line Items]        
Long term supply agreements term of termination notice period 3 years      
Revenue from contract with customer collection terms 75 days