Concentration of Credit Risk (Tables)

12 Months Ended

Sep. 30, 2014

Risks and Uncertainties [Abstract]

Schedule of Account Receivable

Tire manufacturers comprise a significant portion of Cabot’s trade receivable balance. The accounts receivable balance for these significant customers as a group are as follows:

	September 30
	2014		2013
	(Dollars in millions)
Tire manufacturers	$	311	$	298