Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Sep. 30, 2020
Loss Contingencies [Line Items]
(Provision) benefit for income taxes	$ (30.0)		$ 5.0		$ (93.0)	$ (9.0)
Respirator Liabilities [Member]
Loss Contingencies [Line Items]
Respirator liability				$ 65.2
Settlement amount			$ 32.6
Description of pending claims					The Company paid $32.6 million of the settlement during the third quarter of fiscal 2020 and the remaining $32.6 million in the first quarter of fiscal 2021.
Respirator reserve	20.0				$ 20.0		$ 24.0
Respirator Liabilities [Member] | Selling and Administrative Expenses [Member]
Loss Contingencies [Line Items]
Respirator charge				$ 50.0
Respirator Liabilities [Member] | Accounts Payable and Accrued Liabilities [Member]
Loss Contingencies [Line Items]
Settlement amount		$ 32.6
Brazil Indirect Tax Settlements [Member]
Loss Contingencies [Line Items]
(Provision) benefit for income taxes	12.0
Brazil Indirect Tax Settlements [Member] | Net Sales and Other Operating Revenues [Member]
Loss Contingencies [Line Items]
Income tax credit recovery	9.0
Brazil Indirect Tax Settlements [Member] | Other Income (Expense) [Member]
Loss Contingencies [Line Items]
Interest income	$ 3.0