Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Mar. 31, 2014	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2013
Respirator Liabilities [Member]
Loss Contingencies [Line Items]
Number of claimants		41,000		42,000
Respirator reserve on discounted basis		$ 9		$ 11
Respirator reserve on undiscounted basis		13		15
Cash payments for respirator reserves		2	2
Environmental Matters [Member]
Loss Contingencies [Line Items]
Reserved for environmental matters, on an undiscounted basis		17		5
Charge related to environmental matters	13
Cash payments for environmental reserves		$ 2	$ 2