Restructuring Costs (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Mar. 31, 2012	Mar. 31, 2011	Sep. 30, 2011
Balance		$ 19		$ 19	$ 11
Activity during the period:
Charges to continuing operations	3		5	27	8
Charges to discontinued operations	0			1	7
Charges to discontinued operations for Retained Entities					6
Asset impairments and other		(19)		(20)	(1)
Cash payments - continuing operations				(10)	(7)
Cash payments - discontinued operations				(2)	(1)
Other					1
Total restructuring reserves	15		17	15	17
Less: non-current restructuring reserves	(5)			(5)
Restructuring reserves - current	10			10		16
Employee Severance [Member]
Balance		19		19	11
Activity during the period:
Charges to continuing operations				6	7
Charges to discontinued operations				0
Charges to discontinued operations for Retained Entities					6
Asset impairments and other				(1)	0
Cash payments - continuing operations				(9)	(7)
Cash payments - discontinued operations				(1)	(1)
Other					1
Total restructuring reserves	14		17	14	17
Less: non-current restructuring reserves	(5)			(5)
Restructuring reserves - current	9			9
Impairment In Value Of Asset [Member]
Balance		0		0	0
Activity during the period:
Charges to continuing operations				19	1
Charges to discontinued operations				0
Charges to discontinued operations for Retained Entities					0
Asset impairments and other				(19)	(1)
Cash payments - continuing operations				0	0
Cash payments - discontinued operations				0	0
Other					0
Total restructuring reserves	0		0	0	0
Less: non-current restructuring reserves	0			0
Restructuring reserves - current	0			0
Plant Shutdown and Other [Member]
Balance		0		0	0
Activity during the period:
Charges to continuing operations				2	0
Charges to discontinued operations				1
Charges to discontinued operations for Retained Entities					0
Asset impairments and other				0	0
Cash payments - continuing operations				(1)	0
Cash payments - discontinued operations				(1)	0
Other					0
Total restructuring reserves	1		0	1	0
Less: non-current restructuring reserves	0			0
Restructuring reserves - current	$ 1			$ 1