Guarantees (Income Statement) (Details) - USD ($) $ in Millions	12 Months Ended
Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2019
Guarantor Obligations
Investment earnings from AFSI	$ 4.2	$ 5.2	$ 2.2
Advanced Filtration Systems Inc.
Guarantor Obligations
Investment earnings from AFSI	1.8	2.2	(0.3)
Royalty \| Advanced Filtration Systems Inc.
Guarantor Obligations
Royalty income from AFSI	$ 6.9	$ 6.8	$ 6.5

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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+ Details