Long-Term Debt (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Sep. 30, 2011
Debt	$ 975	$ 1,034
Less: current maturities	(21)	(84)
Long-term debt	954	950
8-3/4 percent notes due 2012 [Member]
Debt	0	84
8-1/8 percent notes due 2015 [Member]
Debt	250	250
10-5/8 percent notes due 2018 [Member]
Debt	246	246
4.625 percent convertible notes due 2026 [Member]
Debt	300	300
4.0 percent convertible notes due 2027 [Member]
Debt	200	200
Lines of credit and other [Member]
Debt	12	8
Accounts Receivable Securitization [Member]
Debt	19	0
Unamortized gain on interest rate swap termination [Member]
Debt	11	14
Unamortized discount on convertible notes [Member]
Debt	$ (63)	$ (68)