Debt and Other Obligations - Schedule of Long-Term Obligations (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Jul. 31, 2012	Sep. 30, 2013 Variable Rate Debt [Member]	Sep. 30, 2012 Variable Rate Debt [Member]	Sep. 30, 2013 Fixed Rate Debt [Member]	Sep. 30, 2012 Fixed Rate Debt [Member]	Sep. 30, 2012 Revolving Credit Facility Expiry August 2016 [Member] Variable Rate Debt [Member]	Sep. 30, 2013 Chinese Renminbi Notes, Due Through 2016, 5.40% - 6.77% [Member] Variable Rate Debt [Member]	Sep. 30, 2012 Chinese Renminbi Notes, Due Through 2016, 5.40% - 6.77% [Member] Variable Rate Debt [Member]	Sep. 30, 2009 5% Notes Due 2017 [Member]	Sep. 30, 2013 5% Notes Due 2017 [Member] Fixed Rate Debt [Member]	Sep. 30, 2012 5% Notes Due 2017 [Member] Fixed Rate Debt [Member]	Jul. 31, 2012 2.55% Notes Due 2018 [Member]	Sep. 30, 2013 2.55% Notes Due 2018 [Member] Fixed Rate Debt [Member]	Sep. 30, 2012 2.55% Notes Due 2018 [Member] Fixed Rate Debt [Member]	Sep. 30, 2013 3.7% Notes Due 2022 [Member] Fixed Rate Debt [Member]	Sep. 30, 2012 3.7% Notes Due 2022 [Member] Fixed Rate Debt [Member]	Sep. 30, 2013 Notes Due 2019, 7.42% [Member] Fixed Rate Debt [Member]	Sep. 30, 2012 Notes Due 2019, 7.42% [Member] Fixed Rate Debt [Member]	Sep. 30, 2013 Notes Due 2022, 8.346% - 8.47% [Member] Fixed Rate Debt [Member]	Sep. 30, 2012 Notes Due 2022, 8.346% - 8.47% [Member] Fixed Rate Debt [Member]	Sep. 30, 2013 Note Due 2028, 6.57% - 7.28% [Member] Fixed Rate Debt [Member]	Sep. 30, 2012 Note Due 2028, 6.57% - 7.28% [Member] Fixed Rate Debt [Member]	Dec. 31, 2003 Eurobond, Due 2013, 5.25% [Member]	Sep. 30, 2012 Eurobond, Due 2013, 5.25% [Member] Fixed Rate Debt [Member]	Sep. 30, 2013 Guarantee Of Employee Stock Option Plan Note Due On Two Thousand And Fourteen [Member] Fixed Rate Debt [Member]	Sep. 30, 2012 Guarantee Of Employee Stock Option Plan Note Due On Two Thousand And Fourteen [Member] Fixed Rate Debt [Member]	Sep. 30, 2013 Chinese Renminbi Notes, Due Through 2018, 4.68% - 6.65% [Member] Fixed Rate Debt [Member]	Sep. 30, 2012 Chinese Renminbi Notes, Due Through 2018, 4.68% - 6.65% [Member] Fixed Rate Debt [Member]	Sep. 30, 2013 Capital Lease Obligations, Due Through 2031 [Member]	Sep. 30, 2012 Capital Lease Obligations, Due Through 2031 [Member]
Debt Instrument [Line Items]
Capital lease obligations, due through 2031	$ 18	$ 16																													$ 18	$ 16
Unamortized debt discount	(2)	(2)	(1)								(2)			(1)											(1)
Total debt	1,034	1,357		47	200	971	1,143	189	47	11		300	300		250	250	350	350								177	2	8	16	5
Less current portion of long-term debt	(14)	(185)
Total Medium Term Notes						53	53												30	30	15	15	8	8
Total long-term debt	$ 1,020	$ 1,172