Accumulated Other Comprehensive Loss - Amounts Reclassified Out of AOCI (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Settlement costs	$ (27)
Income from continuing operations before income taxes and equity in earnings of affiliated companies	51	109
Tax impact	3	24
Income from continuing operations	49	87
Reclassification Out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Settlement costs	27
Income from continuing operations before income taxes and equity in earnings of affiliated companies	27
Tax impact	(6)
Income from continuing operations	21
Reclassification Out of Accumulated Other Comprehensive Income [Member] | Pension and Other Postretirement Benefit Liability Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of actuarial losses	1	1
Amortization of prior service cost	$ (1)	$ (1)