Stockholders' Equity - Schedule of Company’s Share Activity (Details)	3 Months Ended
	Jul. 31, 2026 $ / shares shares	Jul. 31, 2025 shares	Apr. 30, 2026 $ / shares	Apr. 30, 2026 £ / shares	Apr. 30, 2025 $ / shares
Common Stock
Beginning balance (in shares)	410,272,086
Ending balance (in shares)	409,867,481
Treasury stock:
Beginning balance treasury stock (in shares)	3,693,501
Ending balance treasury stock (in shares)	4,635,333
Common stock held by the ESOT:
Beginning balance (in shares)	410,272,086
Ending balance (in shares)	409,867,481
Common stock, par value (in dollars per share) \| (per share)	$ 0.01		$ 0.01	£ 0.10	$ 0.18
Treasury Stock
Common Stock
Settlement of stock-based compensation (in shares)	216,832	0
Treasury stock:
Beginning balance treasury stock (in shares)	3,693,501	20,111,957
Repurchase of common stock (in shares)	725,000	5,425,460
Settlement of stock-based compensation (in shares)	216,832	0
Ending balance treasury stock (in shares)	4,635,333	25,537,417
Common stock held by the ESOT:
Settlement of stock-based compensation (in shares)	(216,832)	0
Repurchase of common stock (in shares)	725,000	5,425,460
Common stock held by the ESOT
Common Stock
Beginning balance (in shares)	0	534,660
Settlement of stock-based compensation (in shares)	0	461,036
Ending balance (in shares)	0	364,512
Treasury stock:
Repurchase of common stock (in shares)	0	290,888
Settlement of stock-based compensation (in shares)	0	461,036
Common stock held by the ESOT:
Beginning balance (in shares)	0	534,660
Settlement of stock-based compensation (in shares)	0	(461,036)
Repurchase of common stock (in shares)	0	290,888
Ending balance (in shares)	0	364,512
Ashtead Share Capital \| Common Stock
Common Stock
Beginning balance (in shares)	0	451,354,833
Ending balance (in shares)	0	451,354,833
Common stock held by the ESOT:
Beginning balance (in shares)	0	451,354,833
Ending balance (in shares)	0	451,354,833
Sunbelt Rentals Common Stock \| Common Stock
Common Stock
Beginning balance (in shares)	413,965,587	0
Settlement of stock-based compensation (in shares)	537,227	0
Ending balance (in shares)	414,502,814	0
Treasury stock:
Settlement of stock-based compensation (in shares)	537,227	0
Common stock held by the ESOT:
Beginning balance (in shares)	413,965,587	0
Settlement of stock-based compensation (in shares)	(537,227)	0
Ending balance (in shares)	414,502,814	0