Commitments And Contingencies (Schedule Of Raw Material Purchased Under Long Term Purchase Agreements) (Details) (USD $) In Millions	12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Raw material purchased	$ 358	$ 336	$ 222
Core Segment [Member]
Raw material purchased	340	294	136
Performance Segment [Member]
Raw material purchased	18	36	82
Specialty Fluids Segment [Member]
Raw material purchased		$ 6	$ 4