Accumulated Other Comprehensive Income - Schedule of Accumulated Other Comprehensive Income (Loss) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive (loss) income, beginning balance	$ (516)
Other comprehensive income before reclassifications	6
Amounts reclassified into income	10
Accumulated other comprehensive (loss) income, ending balance	(500)
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive (loss) income, beginning balance	74
Other comprehensive income before reclassifications	6
Accumulated other comprehensive (loss) income, ending balance	80
Benefit Plans Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive (loss) income, beginning balance	(558)
Other comprehensive income before reclassifications
Amounts reclassified into income	9	14
Accumulated other comprehensive (loss) income, ending balance	(549)
Unrealized Losses on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive (loss) income, beginning balance	(31)
Other comprehensive income before reclassifications
Amounts reclassified into income	1	1
Accumulated other comprehensive (loss) income, ending balance	$ (30)