Commitments and Contingencies - Additional Information (Detail)	12 Months Ended
	Sep. 30, 2018 USD ($) claimants	Sep. 30, 2017 USD ($) claimants	Sep. 30, 2016 USD ($)
Loss Contingencies [Line Items]
Lease expiration period, years	10 years
Rent expense under such operating lease agreement	$ 32,000,000	$ 33,000,000	$ 31,000,000
Raw material purchased	441,000,000	$ 331,000,000	268,000,000
Long term purchase commitment related to information technology	$ 14,000,000
Purchase agreement period	5 years
Charges for environmental expense	$ 6,000,000
Respirator Liabilities [Member]
Loss Contingencies [Line Items]
Annual fees paid by transferee to transferor company	$ 400,000
Number of claimants | claimants	35,000	37,000
Respirator reserve	$ 25,000,000	$ 18,000,000
Cash payments for respirator reserves	3,000,000	3,000,000	3,000,000
Respirator Liabilities [Member] | Selling and Administrative Expenses [Member]
Loss Contingencies [Line Items]
Respirator charge	10,000,000	0	13,000,000
Accounts Payable and Accrued Liabilities [Member]
Loss Contingencies [Line Items]
Reserve for environmental matters included in accrued expenses	12,000,000
Environmental Matters [Member]
Loss Contingencies [Line Items]
Reserved for environmental matters	15,000,000	12,000,000
Reserve for environmental matters included in accrued expenses	12,000,000	2,000,000
Reserve for environmental matters included in other liabilities	3,000,000	10,000,000
Cash payments for environmental reserves	3,000,000	2,000,000	2,000,000
Environmental Matters [Member] | Operating and Maintenance Component [Member]
Loss Contingencies [Line Items]
Reserved for environmental matters	3,000,000
Per Accident for Auto [Member]
Loss Contingencies [Line Items]
Self-insured liability	500,000
Per Occurrence for All Other [Member]
Loss Contingencies [Line Items]
Self-insured liability	2,000,000
Per Accident for U.S. Workers' Compensation [Member]
Loss Contingencies [Line Items]
Self-insured liability	1,000,000
Maximum [Member]
Loss Contingencies [Line Items]
Retention for medical costs per person per annum	250,000
Charges for environmental expense		1,000,000	1,000,000
Non-Controlling Interests [Member]
Loss Contingencies [Line Items]
Raw material purchased	156,000,000	116,000,000	$ 92,000,000
Accounts payable and accrued liabilities	$ 8,000,000	$ 12,000,000