Revenue Recognition - Summary of Contract Balances (Detail) - USD ($) $ in Millions		12 Months Ended
		Aug. 31, 2023	Aug. 31, 2022
Contract With Customer Asset And Liability [Line Items]
Contract liabilities	[1]	$ 43.3	$ 30.5	[2]
Change in contract liabilities		12.8
Accounts Receivable, Net
Contract With Customer Asset And Liability [Line Items]
Contract assets		0.1	13.0	[2]
Change in contract assets		(12.9)
Inventories
Contract With Customer Asset And Liability [Line Items]
Contract assets		7.0	$ 6.0
Change in contract assets		$ 1.0

[1] Contract liabilities balance includes deferred revenue within the scope of Revenue from Contracts with Customers (Topic 606).

[2] August 31, 2022 balances include contract assets and liabilities associated with Gunderson Marine which was disposed of in May 2023. See Note 5 for further discussion.