Restructuring Costs (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014		Mar. 31, 2015	Mar. 31, 2014	Sep. 30, 2014
Restructuring Reserve [Roll Forward]
Beginning balance				$ 11	$ 12
Charges to continuing operations	3	2	[1]	6	3
Cash payments – continuing operations				(3)	(4)
Other				(2)	(1)
Total restructuring reserves	12	10		12	10
Less: non-current restructuring reserves	(2)	(3)		(2)	(3)	(2)
Restructuring reserves – current	10	7		10	7	9
Employee Termination Benefits
Restructuring Reserve [Roll Forward]
Beginning balance				11	12
Charges to continuing operations				6	3
Cash payments – continuing operations				(3)	(4)
Other				(2)	(1)
Total restructuring reserves	12	10		12	10
Less: non-current restructuring reserves	(2)	(3)		(2)	(3)
Restructuring reserves – current	10	7		10	7
Asset Impairment
Restructuring Reserve [Roll Forward]
Beginning balance				0	0
Charges to continuing operations				0	0
Cash payments – continuing operations				0	0
Other				0
Total restructuring reserves	0	0		0	0
Less: non-current restructuring reserves	0	0		0	0
Restructuring reserves – current	0	0		0	0
Plant Shutdown & Other
Restructuring Reserve [Roll Forward]
Beginning balance				0	0
Charges to continuing operations				0	0
Cash payments – continuing operations				0	0
Other				0	0
Total restructuring reserves	0	0		0	0
Less: non-current restructuring reserves	0	0		0	0
Restructuring reserves – current	$ 0	$ 0		$ 0	$ 0

[1] Amounts for prior periods have been recast for discontinued operations.