Accumulated Other Comprehensive (Loss) Income - Amounts Reclassified Out of Accumulated Other Comprehensive (Loss) Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from continuing operations before income taxes and equity in (loss) earnings of affiliated companies	$ 71	$ 80	$ 48	$ 109	$ 56	$ 74	$ 37	$ 43	$ 308	$ 210	$ 246
Tax impact	41	20	7	24	8	16	16	20	92	60	55
Income from continuing operations									216	161	202
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from continuing operations before income taxes and equity in (loss) earnings of affiliated companies									0	2	1
Tax impact									0	0	0
Income from continuing operations									0	2	1
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									3	5	4
Amortization of prior service cost									$ (3)	$ (3)	$ (3)