Commitments and Contingencies - Additional Information (Detail) - Respirator Liabilities [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2020	Sep. 30, 2019
Loss Contingencies [Line Items]
Respirator liability	$ 65.2		$ 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, which is included in Accounts payable and accrued liabilities on the Consolidated Balance Sheets as of June 30, 2020, will be paid in the first quarter of fiscal 2021.
Respirator reserve	21.0		$ 21.0	$ 35.0
Selling and Administrative Expenses [Member]
Loss Contingencies [Line Items]
Respirator charge		$ 50.0
Accounts Payable and Accrued Liabilities [Member]
Loss Contingencies [Line Items]
Respirator liability	$ 32.6		$ 32.6